Question

Calcule o seguinto produto (6+3i)(2+i)

Answer 1

$(6+3i)(2+i)=\\ \\=12+6i+6i+3i^2=\\ \\=12+12i+3\cdot(-1)=\\ \\=12-3+12i=\\ \\=9+12i$

Answer 2

(6+3i) (2+i)

(12+6i) (6i+3i(2))

12+6i+6i-3 (-3porq 1 (2) =-1)

12-3+12i

9+12i