Algebra practice question

Answer: -4

Substitute (a, 6): 2a + 18 = 10 → a = −4. Check with (a + 3, 4) = (−1, 4): −2 + 12 = 10. ✓

Common wrong answers

If you answered 4

4 has the wrong sign: 2a = 10 − 18 = −8.

If you answered -1

−1 is a + 3, the x-coordinate of the second point.

If you answered -8

−8 is 2a, before dividing by 2.

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