Question

10) Calcule as operações:

a) (2 + 5i) + (3 + 4i) b) (1 + i) - (1 - i) c) (1+2i). (-1+3i)​

Answer 1

Resposta:

a) $z=(2+5i)+(3+4i)\\z=2+5i+3+4i\\z=2+3+5i+4i\\z=5+9i$     b) $z=(1+i)-(1-i)\\z=(1-1)+(1+1)i\\z=0+2i\\z=2i$

c) $z=(1+2i).(-1+3i)\\z=\left(1\cdot \left(-1\right)-2\cdot \:3\right)+\left(1\cdot \:3+2\left(-1\right)\right)i\\z=-7+i$