Question

What is the solution to the system of linear equations?

2x + y = 7
x - 2y = 16
A)(4,-1)
B)(-1,9)
C)(6,-5)
D)(-5,6)

Answer 1

(6, -5) (Answer C)

Explanation:

Multiply the first equation by 2. We get the following equivalent system:

4x + 2y = 14

x - 2y = 16

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5x = 30, or x = 6.

Substituting 6 for x in the second equation, we get

6 - 2y = 16, or

- 2y = 10, so that y = -5

and the solution is (6, -5) (Answer C)