Question

calcule ( 1 + i ) ( 2 - i ) ( 3 + 2i)​

Answer 1

$(1+i)\,.\,(2-i)\,.\,(3+2i)~=\\\\\\=~(~(1+i)\,.\,(2-i)~)\,.\,(3+2i)\\\\\\=~(~1\,.\,2~+~1\,.\,(-i)~+~i\,.\,2~+~i\,.\,(-i)~)\,.\,(3+2i)\\\\\\=~(~2-i+2i-i^2~)\,.\,(3+2i)\\\\\\=~(~2+i-(-1)~)\,.\,(3+2i)\\\\\\=~(3+i)\,.\,(3+2i)\\\\\\=~3\,.\,3~+~3\,.\,2i~+~i\,.\,3~+~i\,.\,2i\\\\\\=~9+6i+3i+2i^2\\\\\\=~9+9i+2\,.\,(-1)\\\\\\=~9+9i-2\\\\\\=~\boxed{7+9i}$