Question

What is the solution to the system of equations? Use the linear combination method.

{3x+y=3

{2x+y=7


Enter your answer __,__

Answer 1

(-4,15)

Explanation:

Personally I think this works better with substitution, but I'll do it your way.

3x + y = 3

2x + y = 7 Subtract these two equations

x = - 4 3 - 7 = - 4

3x + y = 3 Substitute - 4 for x

3(-4) + y = 3 Combine

-12 + y = 3 Add 12 to both sides

-12 + 12 + y = 3+12

y = 15

Check

2x + y = 7

2*-4 + 15 = 7

- 8 + 15 = 7

7 = 7

It checks.