Simplify each of the following and express it in the form a + ib :
(3 + 4i) (2 – 3i)
Given: (3 + 4i) (2 – 3i)
Firstly, we open the brackets
3 × 2 + 3 × (-3i) + 4i × 2 – 4i × 3i
= 6 – 9i + 8i – 12i2
= 6 – i – 12(-1) [∵, i2 = -1]
= 6 – i + 12
= 18 – i
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