how is this (n-3)^2 solve?

Question

solving the equation

Answer 1

I believe you mean (n - 3)^2 = 0.

In this case, we have:

(n - 3)^2 = 0
(n - 3)(n - 3) = 0
n - 3 = 0 or n - 3 = 0
n = 3

Suppose you meant that you want to expand (n - 3)^2 out instead. (Note that in this case, this will not be an equation. It will be an expansion.)

We will have:

(n - 3)^2
= (n - 3)(n - 3)
= n(n - 3) - 3(n - 3)
= ((n)(n) - (3)(n)) - ((3)(n) - (3)(3))
= (n^2 - 3n) - (3n - 9)
= n^2 - 3n - 3n + 9
= n^2 - 6n + 9