Algebra practice question

Answer: 0

Substitute x = 2, y = −1. First equation: 2a − 1 = 5, so a = 3. Second: 2 − b = 5, so b = −3. a + b = 0.

Common wrong answers

If you answered 3

3 is a alone.

If you answered 6

6 uses b = 3, missing the sign: 2 + b(−1) = 5 gives −b = 3, b = −3.

If you answered -3

−3 is b alone.

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