Advanced Math practice question

Answer: 6

2x² − 8 = 64 gives 2x² = 72, x² = 36, x = 6.

Common wrong answers

If you answered 18

18 is 36/2, forgetting the square root.

If you answered 36

36 is x², not x.

If you answered 5.3

5.3 is √28, subtracting 8 instead of adding.

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