WAEC 2021 · Paper 1 · Q3

Indices & standard form

Solve $2^{\sqrt{2x + 1}} = 32$ .

Worked solution (try it first)

$32 = 2^5$ , so the powers are equal: $\sqrt{2x + 1} = 5$ .
Square both sides: $2x + 1 = 25$ .
Subtract 1 and halve: $2x = 24$ , so $x = 12$ , option C.

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