The characteristic equation is given by \(\displaystyle{\left({r}^{{2}}\right)}-{4}={0}\) and has the roots \(r_1=2 \text{ and } r_2=-2\). The general solution is given by

\(\displaystyle{y}={c}_{1}{e}^{{2}}{x}+{c}_{2}{e}^{{-{{2}}}}{x}\) where e1 and e2 are arbitrary costant.