Question

Multiply each pair of factors. Type the product in
the space provided
(6 + 3i)(6 - 3i) =​

Answer 1

Explanation:

6*6 - 6*3i + 6*3i -3i*3i

36-18i+18i-9i^2

36-9(-1)= 36+9= 45

Answer 2

`\bf \stackrel{\textit{difference of squares}}{(6+3i)(6-3i)}\implies (6)^2-(3i)^2\implies \stackrel{\textit{recall }i^2=-1}{36-(3^2 i^2)}\implies 36-(9\cdot -1) \\\\\\ 36+9\implies 45`