group your "like" terms together; get the "x"'s on one side, and the numbers on the other, typically the "x"'s on the left equal to the number on the right.
for this one....
5x - 5 = 16 + 2x
1. Subtract 2x from both sides:
5x - 2x - 5 = 16 + 2x - 2x (the 2x's on the right now cancel each other out; they = 0)
3x - 5 = 16
2. Now, add 5 to both sides:
3x - 5 + 5 = 16 + 5
3x = 21
3. Now, you need to divide out the 3 on both sides...
3x/3 = 21/3
x = 7
I'll post a diagram that shows how this works if you need it - I find that understanding why this happens helps internalize the math rather than just "following the rules."
Cheers, mate!
PS - check the answer is correct by putting the 7 back in the original problem, and both sides should equal each other.
5x7 - 5 = 16 + 2x7
35 - 5 = 16 + 14
30 = 30