Question

Solve the following system of equations by using the elimination method. -2x + 9y = -13 6x - 3y = 15

Answer 1

-2x + 9y = -13
(6x - 3y = 15)

16x = 32
x = 2, and then plug x = 2 back into either equation, I will plug it into the first equation, so:
-2(2) + 9y = -13 --> 9y = -9 --> y = -1, so the ordered pair is...(2, -1)

Answer 2

-2x + 9y = -13

3(6x - 3y = 15)
18x - 9y=45


-2x + 9y = -13
+18x - 9y=45
16x=32
16x/16=32/16
x=2


6x - 3y = 15

6(2) - 3y = 15
12-3y=15
12-12-3y=15-12
-3y= 3
-3y/-3=3/-3
y=-1

Check

6x - 3y = 15
6(2) -3(-1)=15
12 +3 = 15
15 = 15