Solve Systems by Substitution

2x+5y=-3

x+8y=4

and

2x+y=7

x-2y=-14

2x + 5y = - 3 ⇒ 2x + 5y = - 3

1x + 8y = 4 ⇒ 2x + 16y = 8

-11y = - 11

-11 - 11

y = 1

2x + 5 (1) = - 3

2x + 5 = - 3

-5 - 5

2x = - 8

2 2

x = - 4

(x, y) = (-4, 1)

2x + 1y = 7 ⇒ 2x + 1y = 7

1x - 2y = - 14 ⇒ 2x - 4y = - 28

5y = 35

5 5

y = 7

2x + 7 = 7

-7 - 7

2x = 0

2 2

x = 0

(x, y) = (0, 7)