WAEC 2021 · Paper 1 · Q16

Make $u$ the subject in $x = \dfrac{2u - 3}{3u + 2}$ .

Worked solution (try it first)

Multiply both sides by $3u + 2$ : $3ux + 2x = 2u - 3$ .
Collect the $u$ terms on the right: $2x + 3 = 2u - 3ux$ , so $2x + 3 = u(2 - 3x)$ .
Divide by $2 - 3x$ : $u = \dfrac{2x + 3}{2 - 3x}$ , option C.