Question

(1+2i)² express the following in the form of (a+ib)

Answer 1

${(1 + 2i)}^{2} \\ = {1}^{2} + {(2i)}^{2} + 2 \times 1 \times 2i \\ = 1 + 4 {i}^{2} + 4i \\ = 1 + 4( - 1) + 4i \\ = 1 - 4 + 4i \\ = - 3 + 4i$

Answer 2

it come in the form of expantion lyk a
$( 1 + 2i) {?}^{2}$