Question

Solve the system of equations.

Give your answer as an ordered pair (x, y)

4x + 8y = 20

-4x + 2y = -30

Answer 1

(7, -1)

Explanation:

4x + 8y = 20 equation 1

-4x + 2y = -30 equation 2

using equation 2 we have:

2y = -30 +4x

y = (-30 +4x)/2

y = -15 +2x equation 3

using equation 3 in equation 1 we have:

4x + 8(-15+2x) = 20

4x - 120 + 16x = 20

20x - 120 = 20

20x = 20+120

20x = 140

x = 140/20

x =7

and we have:

y = -15 +2(7)

y = -15+14

y = -1