Question

Calcule b)(2-3i) - (6-18i)

a)(1-3i) . (2+5i)

Answer 1

b)(2-3i) - (6-18i) = 2 - 3i - 6 + 18i = (2-6) + (18 - 3)i = -4 + 15 i

a)(1-3i) . (2+5i) = 1*2 + 1*5i -3i*2 -3i*5i = 2 + 5i - 6i - 15i² = 2 - i - 15*(-1) = 2 + 15 - i = 17 - i