Advanced Math practice question

Answer: 4

Since 2,187 = 3⁷, the exponents must match: 2x − 1 = 7, so 2x = 8 and x = 4.

Common wrong answers

If you answered 3

3 comes from 2x − 1 = 5, a slip in identifying the power (2,187 is 3⁷, not 3⁵).

If you answered 7

7 is the exponent on 3, which equals 2x − 1, not x.

If you answered 4.5

4.5 comes from 2x = 9 — the −1 was subtracted from 7 rather than added: 7 + 1 = 8.

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