Brackets indicate it goes along with the variable, not multiplied except for (-3)

A sequence $\{x(i)\}$ is defined by $x(1) = 11, x(2) = 23$ and $x(n) = x(n-1) +12x(n-2)$ for all $n \geq 3$.

Prove for all $n∈ℕ, x(n) = 2\times4^n - (-3)^n$.