Advanced Math practice question

Answer: 3

Expand: 2x² − 10x + ax − 5a = 2x² + (a − 10)x − 5a. Matching: a − 10 = −7 gives a = 3, and −5a = −15 confirms it.

Common wrong answers

If you answered 7

7 reads the x-coefficient as a itself.

If you answered 15

15 reads the constant as a; the constant is −5a.

If you answered -3

−3 comes from a − 10 = −7 solved as a = −3 (sign slip); −5a must be −15, so a = 3.

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