Question

Which ordered pair is a solution to the system of equations?

{2x−y=−12x−4y=8


(7, −5)

(1, 3)

(8, 2)

(−2, −3)

Answer 1

(-2,-3)

Explanation:

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Answer 2

(-2, -3)

Explanation:

We assume your system of equations is ...

• 2x - y = -1
• 2x -4y = 8

You can subtract the second equation from the first to get

... (2x -y) -(2x -4y) = (-1) -(8)

... 3y = -9 . . . . . collect terms

... y = -3 . . . . . . divide by 3 . . . . this is sufficient to identify the correct answer

Substituting into the first equation, we have ...

... 2x -(-3) = -1

... 2x = -4 . . . . . add -3

... x = -2 . . . . . . .divide by 2

Now, we're sure the answer is (x, y) = (-2, -3).