Question

Which expression is equivalent to (4 + 7i)(3 + 4i)?
–16 + 37i
12 – 28i
16 – 37i
37 + 16i

Answer 1

well first you will multiply:
4 by 3 to get 12, 4 by 4 to get 16, 7 by 3 to get 21 and 4 by 7 to get 28
put them together
12+16i+21i-28
put the like terms together
(12-28)+(16i+21i)
and simplify
-16+37i
:)