help pls take your time..

Answer:

7mph

Step-by-step explanation:

Given

Time Taken to go upstream Tup = 35 min

Time Taken to go downstream Tdown=21 min.

Let the absolute speed (i.e speed relative to the stationary riverbed) be :

Vup : going upstream

Vdown: going downstream.

We know that the distance traveled upstream = distance traveled downstream, hence we can equate both distances, i.e. :

Distance Traveled Upstream = Distance Traveled Downstream

Vup · Tup = Vdown · Tdown   (substituting the values for time above)

35Vup = 21Vdown

Vup = (21/35) Vdown ------------(eq 1)

We are also given that the motorboat can travel at V = 28 mph relative to the water.

Since going upstream, we are going AGAINST the current, relative to the riverbed, we expect to be travelling slower. In fact, the absolute difference between the speed relative to the water (i.e V = 28 mph) and the speed relative to the seabed (i.e Vup), is equal to the speed of the current.

The same can be said for going downstream WITH the current, that the absolute difference between V = 28mph and Vdown is also equal to the speed of the current.

Hence we can equate the two:

28 - Vup = Vdown - 28

Vup + Vdown = 2(28)

Vup + Vdown = 56 ---------------------(eq 2)

If we solve the system of equations (eq 1) and (eq2), we will get

Vup = 21 mph and Vdown = 35 mph

(sanity check tells us that this makes sense because we expect to be going slower upstream because we are going against the current)

Hence current speed

= 28-Vup

= 28 - 21

= 7 mph. (answer)

Sanity Check:

Current speed can also be written:

= Vdown-28

= 35 - 28

= 7 mph (same as what we found above, so this checks out)

The speed of the current motorboat = 7 mph

Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.

Speed of boat in still water = 28 mph

Let the speed of stream = w

Here, The upstream time is 35 min = 35/60 h = 7/12 h

downstream time is 21 min = 21/60 h = 7/20 hours

Since, The distance (d = vt) traveled either way is the same, but at different speeds and times.

Hence, Set upstream and downstream distances (vt) equal and solve for w as;

⇒ (28 - w)(7/12) = (28 + w)(7/20)

⇒ 20 (28 - w) = 12 (28 + w)

⇒ 5(28 - w) = 3(28 + w)

⇒ 140 - 5w = 84 + 3w

⇒ 140 - 84 = 5w + 3w

⇒ 56 = 8w

⇒ w = 7

Thus, The speed of the current = 7 mph

Learn more about the mathematical expression visit:

brainly.com/question/1859113

#SPJ2

Answer:

its b I belive

Step-by-step explanation:

Answer:

The answer is B.

Step-by-step explanation:

In order to find (f-g)(x), you have to subtract g(x) from f(x) :

[tex]f(x) = {3}^{x} + 10[/tex]

[tex]g(x) = 2x - 4[/tex]

[tex](f - g)(x) = {3}^{x} + 10 - 2x - ( - 4)[/tex]

[tex](f - g)(x) = {3}^{x} + 10 - 2x + 4[/tex]

[tex](f - g)(x) = {3}^{x} - 2x + 14[/tex]

Answer:

[tex]y=50x+75[/tex]

Step-by-step explanation:

When writing a linear equation from a graph, we need to find two things: the y-intercept (what y is when x is 0) and the slope.

First, let us find the y-intercept.

To do this, we can just look at the graph. When x=0, y=75, so 75 is our y-intercept, which is also known as b.

To find the slope of this line, we will need to look at two points

We already know that (0,75) is a point. From the graph, we can see that (1,125) is also a point on this line.

Now, we can find the slope of this line using the following formula [tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]

[tex]m=\frac{125-75}{1-0} \\\\m=\frac{50}{1} \\\\m=50[/tex]

Now that we have both the y-intercept and slope, we can put them together in the form of [tex]y=mx+b[/tex]

[tex]y=50x+75[/tex]

Answer:

Slope: 50

Equation: y = 50x + 75

Step-by-step explanation:

Take two points:

(2,175)

(3,225)

Find the slope:

225 - 175/3 - 2

50/1 = 50

So we get this equation:

y = 50x + b

Now to find b, insert one of those points from before back in:

175 = 50(2) + b

175 = 100 + b

b = 75

So the equation is:

y = 50x + 75

Answer:

Step 3

Step-by-step explanation:

The mistake was made in Step 3.

Step 1: Subtract the wholes. 4 - 1 = 3

Step 2: Subtract the fractions. 5/6 - 3/6 = 2/6

After Step 2, He should have added them instead of subtracting them:

3 + 2/6 = 3 2/6

So, step 3 was his mistake.

Answer:step 3

Step-by-step explanation: he should have added

Answer:

  20%

Step-by-step explanation:

The increase is ...

  $90 -75 = $15

As a percentage of the original price, that is ...

  $15/$75 × 100% = 0.20×100% = 20%

The increase was 20%.

Answer:

object have been reduced by a factor of 4 on paper or the drawing have been increased by a factor of 4 on land .

Step-by-step explanation:

What a scale factor of 1:4 means.

Simply it means that the reals size of the object on land have been reduced in the drawing in the paper.

Now for scale factor of 1:4 in particular it means that the object have been reduced by a factor of 4 on paper or the drawing have been increased by a factor of 4 on land .

Example if the drawing has measurements of 4 inches on paper, then on land it will be 16 inches

Answer:

  (-√8, -√6] ∪ [-√2, 0) ∪ (0, √2] ∪ [√6, √8)

Step-by-step explanation:

The inequality resolves into 4 inequalities. There are 4 intervals in the solution.

Starting at the left, for the absolute value argument less than 0:

  2 ≤ -(x^2 -4) . . . . . . . for x^2 -4 ≤ 0

  2 ≤ -x^2 +4

  -2 ≤ -x^2

  2 ≥ x^2 . . . . . . . . . . consistent with the above 4 ≥ x^2

  -√2 ≤ x ≤ √2 . . . . . square root; may be limited by other constraints

For the absolute value argument greater than 0:

  2 ≤ x^2 -4 . . . . . . . for x^2 -4 ≥ 0

  6 ≤ x^2 . . . . . . . . . .consistent with x^2 ≥ 4

  -√6 ≥ x ∪ x ≤ √6 . . . . take the square root

__

The inequality on the right can be written as the compound inequality ...

  -4 < x^2 -4 < 4

  0 < x^2 < 8 . . . . . add 4

  0 < |x| < √8 . . . . take the square root

This resolves to ...

  -√8 < x < 0 ∪ 0 < x < √8

__

So, the solution set is the set of values of x that satisfy these restrictions on x:

  -√2 ≤ x ≤ √2

  x ≤ -√6 ∪ x ≤ √6

  -√8 < x < 0 ∪ 0 < x < √8

That is a collection of 4 intervals:

  (-√8, -√6] ∪ [-√2, 0) ∪ (0, √2] ∪ [√6, √8)

_____

You may be expected to write √8 as 2√2.

__

These intervals are the portions of the red curve that lie between the two horizontal lines. The points on the upper (dashed) line are not part of the solution set. The points on the lower (solid) line are part of the solution set.

Answer:

The maximum height reached by the rocket is of 938.56 feet.

Step-by-step explanation:

The height y, after x seconds, is given by a equation in the following format:

[tex]y(x) = ax^{2} + bx + c[/tex]

If a is negative, the maximum height is:

[tex]y(x_{v})[/tex]

In which

[tex]x_{v} = -\frac{b}{2a}[/tex]

In this question:

[tex]y(x) = -16x^{2} + 230x + 112[/tex]

So

[tex]a = -16, b = 230, c = 112[/tex]

Then

[tex]x_{v} = -\frac{230}{2*(-16)} = 7.1875[/tex]

[tex]y(7.1835) = -16*(7.1835)^{2} + 230*7.1835 + 112 = 938.56[/tex]

The maximum height reached by the rocket is of 938.56 feet.

Answer:

(71.28, 78.72)

Step-by-step explanation:

We have the following information from the statement:

mean (m) = 75

sample standard deviation (sd) = 5

Sample size (n) = 13

Significance level (alpha) = 1 - 0.98 = 0.02

Degrees of freedom for t-d (df) = n - 1 = 13 - 1 = 12

The critical value would be:

t (alpha / 2) / df = T (0.01) / 12 = 2,681 (this for the table)

Margin of error equals:

E = t (alpha / 2) / df * sd / n ^ (1/2), replacing:

E = 2,681 * 5/13 ^ (1/2)

E = 3.72

Therefore, the interval of 98% confidence interval would be:

75 + 3.72 = 78.72

75 - 3.72 = 71.28

(71.28, 78.72)

easy claps!!

Answer: 30=2x+4 and there are 17 girls in the class.

Step-by-step explanation: if x+4=[total girls] and x=[total boys] and 30=[total kids], then x+4+x = 2x+4 = [total kids], since total kids id 30 then our equation is 30 = 2x + 4 and x= 13boys so 30-13= 17girls.

It's BASIC prealgebra so you should probably practice bit more with linear equations!

Answer:

logₐ(420)

Step-by-step explanation:

Answer:

The answer is

[tex] log_{a}(420) [/tex]

Step-by-step explanation:

You have to use Logarithm Law,

[tex] log_{a}(b) + log_{a}(c) ⇒ log_{a}(b \times c) [/tex]

* Take note, number b and c can only be multiplied when they have the same base, a

So for this question :

[tex] log_{a}(6) + log_{a}(70) [/tex]

[tex] = log_{a}(6 \times 70) [/tex]

[tex] = log_{a}(420) [/tex]

Answer:

We can eliminate the second and third options because marking something up doesn't result in a number less than the original. Since we are told to select 3 options and there are 3 answer choices left we select the first, fourth, and fifth statements.

Answer:  24 square units

Explanation: The diagonals are 4+4 = 8 and 3+3 = 6 units long. Multiply the diagonals to get 8*6 = 48. Then divide this in half to get 48/2 = 24.

An alternative is to find the area of one smallest triangle, and then multiply that by 4 to get the total area of the rhombus. You should find the area of one smallest triangle to be 0.5*base*height = 0.5*4*3 = 6, which quadruples to 24.

Answer:

The answer is D

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

Answer:

d) 50

Step-by-step explanation:

40 + 90 + p = 180

p = 50

Answer:

5

Step-by-step explanation:

[tex]\frac{7+x}{9-x}=3\\ 7+x = 3(9-x)\\7+x=27-3x\\x+3x=27-7\\4x=20\\x=5[/tex]

Answer:

11.24

Step-by-step explanation:

If she arrived at 12.15, to find the time of departure we have to deduct 33 mins and the time she spent for photos,18 mins from this to get time of departure.

Total time spent for journey

33mins +18 mins = 51mins

time of departure = 12.15 - 51mins

so the time of departure is 11.24

Answer:

63.25 not an integer

Step-by-step explanation:

HCF(a,b)*LCM(a,b)=ab

11*368=64*x

x=11*368/64

x=63.25 not an integer, one of the given numbers must be incorrect

but you may use this method to find it yourself

Answer: –55x + 570

Step-by-step explanation:

The person above me completely missed the question so this is the right one

Answer:

40% of 160 is 64

Step-by-step explanation:

You can easily find the answer in one step, just multiplying the whole (160) by the percentage (40) divided by 100.

So, 40% of 160 = 160 × 0.4 = 64.

Answer:

64

Step-by-step explanation:

You first have to subtract 40% from 160 and then you subtract that amount with is 96 from 160 and you get your answer 64

Answer:

B.

✔ -4

Step-by-step explanation:

E 2021

Answer:

I just do a' as a sample. You calculate b' and c'

Step-by-step explanation:

[tex]a'=\frac{b\times c}{a\bullet (b\times c)}, b' = \frac{c\times a}{a\bullet (b\times c)}, c' = \frac{a\times b}{a\bullet (b\times c)}[/tex]

Now, calculate b x c

[tex]\left[\begin{array}{ccc}i&j&k\\2&3&1\\1&-1&-2\end{array}\right] =<-5, 5,-5>[/tex]

[tex]a'=\frac{<-5,5,-5>}{<1, 2, 2>\bullet <-5, 5,-5>}=\frac{<-5, 5, -5>}{-5} =<1,-1,1>[/tex]

Answer:

You have 31.43% of your allowance left.

Step-by-step explanation:

This question can be solved using a rule of three.

Your initial amount, of 70, is 100%.

The remaining amount, of 70 - 48 = 22, is x%. So

70 - 100%

22 - x%

[tex]70x = 100*22[/tex]

[tex]x = \frac{100*22}{70}[/tex]

[tex]x = 31.43[/tex]

You have 31.43% of your allowance left.

Answer:

[tex] \bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})[/tex]

And replacing:

[tex] \mu_{\bar X}= 5[/tex]

And the deviation:

[tex] \sigma_{\bar X}= \frac{0.283}{\sqrt{5}}= 0.126[/tex]

And the distribution is given:

[tex] \bar X \sim N(\mu= 0.08, \sigma= 0.126)[/tex]

Step-by-step explanation:

For this case we have the following info given :

[tex] \mu= 5. \sigma^2 =0.08[/tex]

And the deviation would be [tex] \sigma = \sqrt{0.08}= 0.283[/tex]

For this case we select a sample size of n = 5 and the distirbution for the sample mean would be:

[tex] \bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})[/tex]

And replacing:

[tex] \mu_{\bar X}= 5[/tex]

And the deviation:

[tex] \sigma_{\bar X}= \frac{0.283}{\sqrt{5}}= 0.126[/tex]

And the distribution is given:

[tex] \bar X \sim N(\mu= 0.08, \sigma= 0.126)[/tex]

Answer:

[tex]f(theta)=sin(theta) - cos(theta)[/tex] + C

This is my first time doing a double integral, so im only 90% sure in my answer

Step-by-step explanation:

You pretty much want to take the double integral of sinx + cosx

The anti-derivative of sinx = -cosx

The anti-derivative of cosx = sinx

So f' = -cosx + sinx

Now lets take the integral of f':

The anti-derivative of -cosx = sinx

The anti-derivative of sinx = -cosx

So, f(x) = sinx - cosx

============================================================

Work Shown:

I'll use x in place of theta since its easier to type on a keyboard.

f '' (x) = sin(x) + cos(x)

f ' (x) = -cos(x) + sin(x) + C ..... integrate both sides; dont forget the plus C

f ' (0) = 1

f ' (0) = -cos(0) + sin(0) + C

-cos(0) + sin(0) + C = 1

-1 + 0 + C = 1

C = 1+1

C = 2

So,

f ' (x) = -cos(x) + sin(x) + C

turns into

f ' (x) = -cos(x) + sin(x) + 2

----------------------------

Now integrate both sides of the first derivative to get the original f(x) function

f ' (x) = -cos(x) + sin(x) + 2

f(x) = -sin(x) - cos(x) + 2x + D .... apply integral; D is some constant

f(0) = -sin(0) - cos(0) + 2(0) + D

f(0) = 0 - 1 + 0 + D

f(0) = D - 1

f(0) = 2

D-1 = 2

D = 2+1

D = 3

We have f(x) = -sin(x) - cos(x) + 2x + D update to f(x) = -sin(x) - cos(x) + 2x + 3

----------------------------

So f '' (x) = sin(x) + cos(x) becomes f(x) = -sin(x) - cos(x) + 2x + 3 when f(0) = 2 and f ' (0) = 1

The last step is to replace every x with theta so that we get back to the original variable.

f(x) = -sin(x) - cos(x) + 2x + 3   turns into   f(θ) = -sin(θ) - cos(θ) + 2θ + 3

Answer:

Option D is the correct answer.

Step-by-step explanation:

Coefficients od dividend = (4, - 17, - 15)

Dividend [tex]=4x^2 - 17x - 15[/tex]

Divisor x = 5 =>x-5= 0

Coefficients of Quotient = (4, 3)

Quotient [tex]=4x + 3[/tex]

Remainder = 0

Since,

[tex] Dividend = Divisor \times quotient + Remainder\\

\therefore 4x^2 - 17x - 15 = (x - 5)\times (4x + 3) +0 \\

\therefore 4x^2 - 17x - 15 = (x - 5)\times (4x + 3) \\

\therefore( 4x^2 - 17x - 15) \div (x - 5) = (4x + 3)

[/tex]

Hey there! :)

Answer:

Price per cup: $3.5

Price for 18 cups: $63.

Step-by-step explanation:

To find the cost of a single cup of ice cream, we can set up an equation where 'x' equals the price of a cup of ice cream.

30x = 105

Divide both sides by 30:

x = $3.5.

To find the cost of 18 cups, simply multiply this price by 18:

18 × 3.5 = $63 dollars. This is the price for 18 cups of ice cream.

Answer:

The probability that X and Y are both positive and that their sum is less or equal to 1 0.64.

Step-by-step explanation:

It is provided that the random variables X and Y follows a standard normal distribution.

That is, [tex]X,Y\sim N(0, 1)[/tex]

It is also provided that the variables X and Y are statistically independent of each other.

Compute the probability that X and Y are both positive and that their sum is less or equal to 1 as follows:

The mean and standard deviation of X + Y are:

[tex]E(X+Y)=E(X)+E(Y)=0+0=0\\\\SD(X+Y)=\sqrt{V(X)+V(Y)+2Cov(X,Y)}=\sqrt{1+1+0}=\sqrt{2}[/tex]

The probability is:

[tex]P(X+Y\leq 1)=P(X+Y<1-0.50)\ [\text{Apply continuity correction}]\\[/tex]

                       [tex]=P(X+Y<0.50)\\\\=P(\frac{(X+Y)-E(X+Y)}{SD(X+Y)}<\frac{0.50-0}{\sqrt{2}})\\\\=P(Z<0.354)\\\\=0.63683\\\\\approx 0.64[/tex]

*Use the z-table.

Thus, the probability that X and Y are both positive and that their sum is less or equal to 1 0.64.

Answer:

65.1 and 69.1

Step-by-step explanation:

a^2+b^2=c^2

c=95

b=a+4

Solve for a^2+(a+4)^2=95^2

a=65.1

b=a+4=69.1

Answer:

65.1 and 69.1

Step-by-step explanation:

c² = a² + b²

c= 95

a - one leg

b= (a + 4) - second leg

95² = a² + (a + 4)²

9025 = a² + a² + 2*4a + 16

2a² + 8a - 9009 = 0

[tex]a= \frac{-b +/-\sqrt{b^2 - 4ac} }{2a} \\\\a = \frac{-8 +/-\sqrt{8^2 - 4*2*9009} }{2*2} \\\\a=65.1 \ and \ a=- 69.1[/tex]

A leg length can be only positive. a = 65.1

b = 65.1 + 4 = 69.1

Answer:

(d - 4) / c

Step-by-step explanation:

The slope of the line in terms of c and d is (d - 4) / c.

Here, we have,

To find the slope of the line in terms of the coordinates of the point (c, d), we can use the slope-intercept form of a line, y = mx + b, where m represents the slope.

In the given equation, y = kx + 4, we can see that the coefficient of x is k, which represents the slope of the line.

Since the line contains the point (c, d), we can substitute these values into the equation:

d = kc + 4

To isolate the slope term, we rearrange the equation:

d - 4 = kc

Now, divide both sides by c:

(d - 4) / c = k

Therefore, the slope of the line in terms of c and d is (d - 4) / c.

To learn more on slope click:

brainly.com/question/3605446

#SPJ2