Algebra practice question

Answer: 2

Substitute x = k, y = 7: 7 = k · k + 3, so k² = 4 and k = 2 (positive). Check: y = 2x + 3 passes through (2, 7).

Common wrong answers

If you answered 4

4 is k², one step short.

If you answered 7

7 is the y-coordinate of the point, not k.

If you answered -2

−2 also squares to 4, but k must be positive.

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