Question

-x-8y=-18
x +9y=21
A) (-6,3) B) (6, -3)
c) (6,9)
D) (6,3)

Answer 1

A) (-6,3)

Explanation:

-x-8y=-18

x +9y=21

Add the two equations together to eliminate x

-x-8y=-18

x +9y=21

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

y = 3

Now we need to find x

x +9y = 21

Substitute in y

x +9(3) =21

x+27 = 21

Subtract 27 from each side

x+27-27 = 21-27

x = -6