Question

Z=(3+4i)(3-4i) выполнить умножение

Answer 1

$z = (3 + 4i)(3 - 4i) = \\ = {3}^{2} - {(4i)}^{2} = 9 - {4}^{2} {i}^{2} = \\ = 9 - 16 \times ( - 1) = 9 + 16 = 25$