Question

Найдите сумму z1+z2 и произведение



a)z1=-8-7i z2=-3i
b)z1=3-3i z2=3+3i

Answer 1

z1+z2=(-8-7i)+(-3i) = -8 -10i.
z1*z2 = (-8-7i)*(-3i) = 24i+21i^2=24i-21 = -21-24i.


z1+z2 = (3-3i)+(3+3i) = 6
z1*z2 = (3-3i)(3+3i) = 9-9i^2=9+9 = 18. Помним, что i^2 = -1.