20 POINTS Solve using Elimination:

7x + 2y = 24

4x + y = 15

Solution = ( , )

(6, -9)

Step-by-step explanation:

Eliminate y (you can do x too, but y is easier for this problem)

To eliminate y we must get 0y

If one is 2y, the other must be -2y to get to 0

Keep the first equation the same

7x + 2y = 24

Multiply all numbers in the second equation by -2 (so y can be -2y)

-8x + -2y = -30

Positive + Negative = Negative

-8x - 2y = -30

Now add/subtract the two equations from each other

7x + 2y = 24

-8x - 2y = -30

-1x + 0y = -6

-1x = -6

Divide both sides by -1 to isolate variable

-1x ÷ -1 = -6 ÷ -1

x = 6

We could simply plug in the x value into one of the equations, but that's substitution - not elimination. Repeat the same steps for x

I will multiply the first equation by 4 to get 28x and the second equation by -7 to get -28x for an answer of 0x

28x + 8y = 96

-28x - 7y = -105

0x + 1y = -9

1y = -9

Divide both sides by 1 to isolate the variable

1y ÷ 1 = -9 ÷ 1

y = -9