1) (4-3i)(1+4i) = 4 + 16i - 3i - 12 = 4 + 13i - 12 = -8 + 13i
2) (-2+5i)(-1-2i) = -2 + 4i + 5i + 10 = -2 + 9i + 10 = 8 + 9i
3) (0.2-0.3i)(0.4+0.5i) = 0.08 - 0.1i + 0.1i - 0.15i^2 = 0.08 + 0.05 = 0.13
1) (4-3i)(1+4i) = 4 + 16i - 3i - 12 = 4 + 13i - 12 = -8 + 13i
2) (-2+5i)(-1-2i) = -2 + 4i + 5i + 10 = -2 + 9i + 10 = 8 + 9i
3) (0.2-0.3i)(0.4+0.5i) = 0.08 - 0.1i + 0.1i - 0.15i^2 = 0.08 + 0.05 = 0.13