Question

como que resolve as contas, eu nao intendo :S 3i.(1-2i) (-7+i).(1+5i)

Answer 1

3i(1-2i)  (-7+i).(1+5i) =
(3i-3)(-12 - 34i)= -36i - 102i^2 + 36 +102i ==> -36i +102+36

-36i + 108 ou -36( i - 108 )

3i(1-2i) = 3i - 3i^2=> 3i + 3


(-7+i).(1+5i)= -7 -35i+i+5i^2 => -7-5 -34i ==> - 12 - 34i