If a = -3, find the value of 3a²

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Step-by-step explanation:

xy = -40 and x + y = 18

=> x(18 - x) = -40

=> 18x - x² = -40

=> x² - 18x - 40 = 0

=> (x - 20)(x + 2) = 0

=> x = 20 or x = -2.

The two numbers 20 and -2.

Answer:

let the numbers be x and y

[tex]xy = - 40 - - - (i) \\ x + y = 18 - - - (ii) \\ from \: (ii) \\ x = 18 - y \\ substitute \: for \: x \: in \: (i) \\ (18 - y)y = - 40 \\ 18y - {y}^{2} = - 40 \\ {y}^{2} - 18y - 40 = 0 \\ use \: the \: quadratic \: equation \: to \: get \: y \\ and \: y \: will \: give \: u \: x[/tex]

x = 20

hence y = 18-20

y = -2

or

x = -2

hence y = 18-(-2)

y = 20

The numbers are -2 and 20

Answer:

exponents first then multiply and subtract after

Step-by-step explanation:

the answer is 5

Answer:

75 + 17 = 92

Step-by-step explanation:

Answer:

a = -12

Step-by-step explanation:

For two lines to meet at a right angle, they are perpendicular to each other. Therefore the product of the slopes of the two lines is -1.

The slope of 3y + x = 0 will be -1/3 (rearrange the terms, 3y = -x and therefore y = -1/3 x).

The slope of 4y + ax + 3 = 0 will be -a/4. (4y = -ax - 3, therefore y = -a/4 x - 3/4)

Since the product of the slopes is -1, we can set up an equation now.

-1/3 * -a/4 = -1

a/12 = -1

a = -12

9514 1404 393

Answer:

  about 3.25 feet

Step-by-step explanation:

The relevant trig relationship is ...

  Sin = Opposite/Hypotenuse

  sin(24°) = height/(8 ft)

  height = (8 ft)sin(24°) ≈ 3.254 ft

The slide is about 3.25 feet high.

Answer: Yes the mixed 3 1/4 is a rational number.

Step-by-step explanation:  

Answer:

?Incomplete question!!

By what means these algebraic expressions are related?

Answer:

a) when x = Raw Score: 42

Standard deviation = σ = -10.3

b) Raw Score: 81

Standard deviation = σ = 2.67

Step-by-step explanation:

Find the standard deviation if the mean of a sample is 72, a z-score of 3

Z score formula is given :

z = (x-μ)/σ,

where

x is the raw score

μ is the population mean = 73

σ is the population standard deviation

z = 3

a) when x = Raw Score: 42

z = (x-μ)/σ

3 = 42 - 73/σ

Cross Multiply

3σ = 42 - 73

3σ = -31

σ = -31/3

σ = -10.3

b) Raw Score: 81

z = (x-μ)/σ

3 = 81 - 73/σ

Cross Multiply

3σ = 81 - 73

3σ = 8

σ = 8/3

σ = 2.67

Step-by-step explanation:

bicycle cost= 310

initial money in savings account= 50

additional money saved per week = 20

number of weeks = w

you have to set up an equation

The equation is...

bicycle cost = additional money saved × w + initial money

Substitute the values

310 = 20w + 50

Solve for w

310 - 50 = 20w +50 - 50

260 = 20w

260÷ 20 = 20w÷ 20

13 = w

It will take 13 weeks for her to have enough money for her bicycle

I hope this helps!!!

Answer:

I think the answer is y = 3x + 12.

Step-by-step explanation:

y = 3 (x - 1) (x - 4)

y = 3x -3 (x - 4)

y = 3x + 12

Answer:

x=2

y=-1

Use the system of equations to solve for it

Answer: C- He made a computation error when he added 10.35+7.6.

Step-by-step explanation:

Noam did not line up the decimals when he was adding 10.35 and 7.6. So if you line up the decimals, you would get 17.95 instead of 17.41.

Answer

C.

Step-by-step explanation:

He made a computation error when he added 10.35+746.

*Cough* E d g e n u i t y *Cough*

Sorry I think I am coming down with something...

*Cough* It's right *Cough*

Please give me brainliest!!

Answer:

B. 15 gallons

Step-by-step explanation:

We don't need an exact answer, so we estimate

To do this, we round

41 is a tens number, so I'm going to round to the nearest 10

40

612.9 is a hundreds number, so I'm rounding to the nearest hundred

600

for EACH gallon, the car drives(roughly) 40 miles. If I have driven(roughly) 600 miles, that means I have used 600/40=15 gallons

Answer:

Step-by-step explanation:

I’d vhvhvmvjvhkvhvkfygjghk

Answer:

x>3

Step-by-step explanation:

-5x+20<5 (move the constant to the right)

-5x<5-20 (calculate)

-5x<-15 (divide both sides)

solution: x>3

hope this helps!

Answer:

B,D,E

Step-by-step explanation:

b-multiply by 2 for both

d- multiply by 7 for both

e-multiply by 11 for both

Answer:

c

Step-by-step explanation:

This is c because the numbers in c are moving down by -5.

Answer:

I would say b

Step-by-step explanation:

-5 times 5 is -25

-5 times -25 is 125 ect

Answer:

Step-by-step explanation:

The dimensions of the container:

The area of the container is:

Answer:

Another way to identify the domain and range of functions is by using graphs. Because the domain refers to the set of possible input values, the domain of a graph consists of all the input values shown on the x-axis. The range is the set of possible output values, which are shown on the y-axis.

Step-by-step explanation:

Hope this helps i would give answer but i dont know what the answer is so sorry but hope this helps you.

Answer:

2300 meters, 3000 yards, 3.2 kilometers, 2.5 miles is smallest distance to longest distance. so the furthest, to the closest would be:

2.5 miles, 3.2 kilometers, 3,000 yards, 2,300 yards

Step-by-step explanation:

I hope this helps :)

Answer:

Y-intercept: (0, 0.4)

X-intercepts: (0.3, 0)

Answer:

The y-intercept is (0, 0.4), and the x-intercept is (0.3, 0)

Step-by-step explanation:

To find the intercepts of the line, you need to see what points lie on the x and y-axis.

Answer:

98

Step-by-step explanation:

Given that:

Total number of tickets sold = 159

Ticket price for child admissions = 5.50

Ticket price for adult admissions = 9.80

Total money spent = 1136.80

To find:

The number of child admissions.

Solution:

Let number of child admissions = [tex]x[/tex]

Let number of adult admissions = [tex]y[/tex]

As per question statement:

[tex]x+y = 159[/tex] ...... (1)

and

Money spent for child admissions = 5.50[tex]x[/tex]

Money spent for adult admissions = 9.80[tex]y[/tex]

[tex]5.50x+9.80y = 1136.80[/tex] ...... (2)

Using equation (1):

[tex]y = 159-x[/tex]

Putting in equation (2) from above:

[tex]5.50x+9.80(159-x) = 1136.80\\\Rightarrow 5.50x+1558.2-9.8x=1136.80\\\Rightarrow 4.3x = 421.4\\\Rightarrow x = \bold{98}[/tex]

Therefore, total number of child admissions is 98.

Answer:

[tex]A.f(x) = x^{2} -2x - 15[/tex]

Step-by-step explanation:

Based on the given information, one can write the quadratic equation in factored form. Since the zeros of the equation are the roots, one can say that;

[tex]y = ( x + 3 )( x - 5)[/tex]

(where x = -3, and x = 5 are the roots)

Now all one has to do is distribute to find the quadratic equation in standard form;

[tex]y = (x + 3) (x - 5)\\y = x^{2} +3x - 5x - 15\\y = x^{2} -2x - 15[/tex]

Answer:

Yes, it can.

Step-by-step explanation:

Every time x increments by 1, y increments by 0.2.

The linear equation that satisfies the given data will be y = 0.2x + 1.2.

A connection between a number of variables results in a linear model when a graph is displayed. The variable will have a degree of one.

The linear equation is given as,

y = mx + c

Where m is the slope of the line and c is the y-intercept of the line.

The table is given below.

x              0                1                2               4

y             1.2              1.4            1.6              2

The line is passing through (0, 1.2). Then the value of 'c' will be

1.2 = m * 0 + c

c = 1.2

The line is also passing through (4, 2). Then the value of 'm' will be

2 = 4m + 1.2

m = 0.2

The linear equation that satisfies the given data will be y = 0.2x + 1.2.

More about the linear equation link is given below.

https://brainly.com/question/11897796

#SPJ3

Answer:

Step-by-step explanation:

Step 1: Find AB Use Pythagoras Theorem

AB = [tex]\sqrt{AC^{2} -BC^{2} } = \sqrt{12^{2} -8^{2} } = \sqrt{80}[/tex]

Step 2: Find the Area of the triangle ABC

Area = [tex]\frac{1}{2}AB.BC = \frac{1}{2}\sqrt{80}.8 = 4\sqrt{80}[/tex] = [tex]16\sqrt{5}[/tex]

Step 3: Find BD. Use the area of the triangle above

Area = [tex]\frac{1}{2}BD.AC[/tex]

We already known the Area and AC so, we just plug all the number in

BD = [tex]\frac{2. Area}{AC}[/tex] =  [tex]\frac{2.16\sqrt{5}}{12}[/tex] = [tex]\frac{8\sqrt{5}}{3}[/tex]

Step 4: Find DC. Use Pythagoras Theorem of the triangle BDC

DC = [tex]\sqrt{BC^{2}-BD^{2} }[/tex] = [tex]\sqrt{8^{2}-(\frac{8\sqrt{5}}{3})^{2}}[/tex] =  [tex]\frac{16}{3}[/tex]

Answer:

-6

Step-by-step explanation:

Answer:

$20,000.00

Step-by-step explanation:

90% = 0.90

18000/0.90 = $20,000

CHECK

0.90 x $20,000 = $18,000

Answer:

Step-by-step explanation:

Area of a circle = π r²

where r = 80/2 = 40 in

plugin value of r=40in into the formula:

Area of a circle = π r²

                         = π (40)²

                         = 5027 in²

Given that,

Michael is leaving a 15% tip for his waitress.

To find,

What percent of the  original price will he pay.

Solution,

Let the original price was 100%.

When he leaves a 15% tip for the waitress, he is really paying 100%+15%=115% of the original price.

[tex]115\%=\dfrac{115}{100}\\\\=1.15[/tex]

or

[tex]\dfrac{115}{100}=\dfrac{23}{20}[/tex]

So, this is the required solution.

Given :

Kim drives 156 miles from rother ham to London she drives at an average speed of 60 miles per hour she leaves rother ham at 7:30 am .

To Find :

Can she arrive before 10:00 am.

Solution :

Time taken to cover 156 miles with speed of 60 miles per hour.

[tex]t= \dfrac{Distance}{Time\ taken}\\\\t = \dfrac{156}{60}\ hour\\\\t = 2.6\ hours[/tex]

To arrive before 10:00 am she has only 2.5 left.

But time taken is 2.6 hours which is greater than 2.5 hours.

Therefore, Kim cannot arrive there before 10:00 am.

Answer:

10am

Step-by-step explanation: