Question

Simplify (4 – 5i)(3 + 7i) and write the answer in the form a + bi, where a and b are real numbers.

Answer 1

Use foil to multiply the complex numbers:

(4 - 5i)(3 + 7i) = 12 - 15i + 28i -35i^2

Now simplify:
12 + 13i - 35i^2
= 12 + 13i + 35
= 47 + 13i

Answer 2

This is what I got too! Thanks for verifying my work!