Question

help ASAP will mark brainlist​

Answer 1

Hi there!

$\large\boxed{-40 + 20i}$

Recall the rules for the imaginary number "i":

i = √-1          i² = -1

Given:

(5i) (5i) + (5i) (4 + 3i)

Multiply:

(25i²) + 20i + 15i²

Simplify using the rule above:

25(-1) + 20i + 15(-1)

-25 + 20i - 15

-40 + 20i

a = -40

b = 20