WAEC Further Mathematics 2017 Paper

$3^{2x} - 3^{x+2} = 3^{x+1} - 27$

= $(3^{x})^{2} - (3^{x}).(3^{2}) = (3^{x}).(3^{1}) - 27$

Let $3^{x}$ be B; we have

= $B^{2} - 9B - 3B + 27 = B^{2} - 12B + 27 = 0$.

Solving the equation, we have B = 3 or 9.

$3^{x} = 3$ or $3^{x} = 9$

$3^{x} = 3^{1}$ or $3^{x} = 3^{2}$

Equating, we have x = 1 or 2.