Advanced Math practice question

Answer: 25

Add 3: 2√x = 10. Divide by 2: √x = 5. Square: x = 25. Check: 2(5) − 3 = 7.

Common wrong answers

If you answered 4

4 is (7 − 3)/2 = 2 squared — the 3 was subtracted instead of added. From 2√x − 3 = 7, add 3.

If you answered 5

5 is √x, one step short. Square it to get x = 25.

If you answered 100

100 comes from squaring 10 before dividing by 2 (that is, x = (2√x)² wrongly). Divide first: √x = 5.

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