exponential function questions

$\dfrac 8 q + 2 = \dfrac{q+4}{q-1} \\ \dfrac{8+2q}{q} = \dfrac{q+4}{q-1} \\ (8+2q)(q-1) = q(q+4) \\ 2q^2+6q-8 = q^2 + 4q \\ q^2 + 2q-8=0 \\ (q+4)(q-2) = 0 \\ q= -4, ~2$