Answer:
The answers are:
−6(3i)(−2i) = 36 × —1 = —36, and
2(3 – i)(−2 + 4i) = —4 + 28i
Step-by-step Explanations:
(i) −6(3i)(−2i) = —6 × 3i × —2i = —18i × —2i = 36i²
But we know that i² = —1
Therefore, −6(3i)(−2i) = 36 × —1 = —36
(ii) 2(3 – i)(−2 + 4i) = (6 — 2i)(—2 + 4i) = —12 + 24i + 4i — 8i² = —12 + 28i — 8i²
But i² = —1
Therefore, 2(3 – i)(−2 + 4i) = —12 + 28i — 8i² = —12 + 28i — 8 (—1) = —12 + 28i + 8 = —4 + 28i.