Advanced Math practice question

Answer: 18

(√8 + √2)² = 8 + 2√16 + 2 = 8 + 8 + 2 = 18. (Or note √8 = 2√2, so the sum is 3√2 and its square is 18.)

Common wrong answers

If you answered 10

10 is 8 + 2, forgetting the cross term.

If you answered 14

14 uses a cross term of 4 instead of 8.

If you answered 16

16 is (√16)², squaring the product instead of the sum.

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