Advanced Math practice question

Answer: 8

x² − x = 56 gives x² − x − 56 = 0 = (x − 8)(x + 7); the positive root is 8.

Common wrong answers

If you answered 7

Check: 49 − 7 = 42, not 56. The factors of −56 differing by 1 are −8 and 7.

If you answered 56

56 is the stated gap, not the number itself.

If you answered -7

−7 solves the quadratic but is not positive.

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