Advanced Math practice question

Answer: 10

a² − b² = (a − b)(a + b) = 2(a + b) = 20, so a + b = 10.

Common wrong answers

If you answered 5

5 halves 10.

If you answered 12

12 comes from adding 2 to 10.

If you answered 20

20 is the difference of the squares.

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