Question

Solve by subtraction y=-2x-4
y=2x-12

please show work!

Answer 1

(2, -8)

Explanation:

Add the two equations to solve. The x-values are cancelled out. Solve for y.

y = -2x - 4

+ y = 2x - 12

2y = -16

y = -8

Now, plug in the y-value into one of the equations to solve for x.

y = 2x - 12

-8 = 2x - 12

(-8) + 12 = (2x - 12) + 12

4 = 2x

(4)/2 = (2x)/2

x = 2

The solution is (2, -8).

Answer 2

x=2, y = -8

Explanation:

y=-2x-4

y=2x-12

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

Subtract the two equations

y=-2x-4

-y=-2x+12

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

0 = -4x +8

Subtract 8 from each side

-8 = -4x+8-8

-8 = -4x

Divide by -4

-8/-8 = -4x/-4

2 =x

Then solve for y

y = -2x-4

y = -2(2) -4

y = -4-4

y = -8