JAMB 1986 · UME · Q27✱✱

Make $v$ the subject of the formula $S^2 = \frac{6}{v} - \frac{w}{2}$ .

Worked solution (try it first)

Multiply every term by 2 to clear the halves: $2S^2 = \frac{12}{v} - w$ .
Add $w$ to both sides: $\frac{12}{v} = 2S^2 + w$ .
Turn both sides upside down and multiply by 12: $v = \dfrac{12}{2S^2 + w}$ , option D.