Question

{2x+3y=−7, 7x+9y=−14
Answer as an ordered pair (x,y).

Answer 1

Explanation:

2x + 3y = -7

7x + 9y = -14

-3(2x+3y= -7) = -6x - 9y = 21

-6x - 9y = 21

7x + 9y = -14

add columns (y values cancel)

1x + 0y = 7

x = 7

plug 7 into the x value in either equation to find y

2(7) + 3y = -7

14 + 3y = -7

3y = -21

y = -7

(x,y) = (7,-7)