1. I assume that you want to solve

If so

Let x-3 = y. Then your equation becomes:

A product of 2 factors equals zero if one factor equals zero:

That means: x-3 = 0 ==> x = 3 or x-3=2 ==> x = 5

You must plug in the result into the original equation to check if the result is a valid solution:

x = 3:

x = 5:

Therefore: Only x = 3 is a solution.