Question

dados os complexos u=2+3i, v= -1+4i e w= 5i. Calcule:
a) u+v    b) (u+v)w   c) (u+v) (u-v)

Answer 1

a) u+v = 2 + 3i -1 + 4i  ==> 1 + 7i


b) (u+v)w = (2+3i-1+4i)(5i) ==> ( 1 + 7i)(5i)==> 5i +35i^2 => 5i - 35


c) (u+v) (u-v) =  (1 + 7i)( 3 - i)==> 3 - i + 21i - 7i^2==>3+7 +20i==> 10 + 20i

u - v = 2+3i -(-1+4i) ==> 2+3i +1 - 4i ==> 3 - i