WAEC 2022 · Paper 1 · Q18

Make $t$ the subject of $k = m\sqrt{\dfrac{t - p}{r}}$ .

Worked solution (try it first)

Divide by $m$ and square both sides: $\frac{k^2}{m^2} = \frac{t - p}{r}$ .
Multiply by $r$ : $t - p = \frac{k^2r}{m^2}$ .
Add $p$ , writing it over $m^2$ : $t = \frac{k^2r}{m^2} + \frac{pm^2}{m^2}$
$= \dfrac{k^2r + pm^2}{m^2}$ , option B.