Question

PLEASE HELP ME !!!

Which equation results from adding the equations in this system?

-8 x + 8 y = 8.
3 x - 8 y = -18.


A) 5 x = -10

B) 5 x = 26

C) -5 x = 26

D) -5 x = -10

Answer 1

-5x = -10

Explanation:

Take the x terms, y terms and constants separately.

x: -8x + 3x = 3x - 8x = -5x

y: 8y + (-8y) = 8y - 8y = 0

Constant: 8 + (-18) = 8 - 18 = -10

Take all sums together

-5x + 0 = -10

-5x = -10

Answer 2

D

Explanation:

Given the 2 equations

- 8x + 8y = 8

3x - 8y = - 18

Adding the 2 equations term by term gives

(- 8x + 3x) + (8y - 8y) = (8 - 18), that is

- 5x + 0 = - 10, that is

- 5x = - 10 → D