Question Number 61886 by aliesam last updated on 10/Jun/19
$${a}+{bi}=\frac{\mathrm{2}+{i}}{\mathrm{1}−{i}} \\ $$$${find}\: \\ $$$$\mathrm{2}\left({a}^{\mathrm{2}} +{b}^{\mathrm{2}} \right) \\ $$
Answered by MJS last updated on 10/Jun/19
$$\frac{\mathrm{2}+\mathrm{i}}{\mathrm{1}−\mathrm{i}}=\frac{\mathrm{1}}{\mathrm{2}}+\frac{\mathrm{3}}{\mathrm{2}}\mathrm{i} \\ $$$$\mathrm{2}\left({a}^{\mathrm{2}} +{b}^{\mathrm{2}} \right)=\mathrm{5} \\ $$