Question

Find the product of (x+9i)^2

Answer 1

Just think of the i as a variable for right now. What do you get when you expand it?

You can use this identity:
(a+b)^2 = a^2 + 2ab + b^2

Answer 2

(x + 9i)(x + 9i)
x^2 + 9xi + 9xi + 81i^2
x^2 + 18xi - 81

Answer 3

Good job! That's the final answer :)

Answer 4

x^2 + 18xi - 81
Is the final answer correct?

Answer 5

Yes