If you are adding variables, say x + 2x, would you also add the variables, to make it squared instead of just another x?
No.......this used to confuse me, too....
The power [exponent] on the variables remains the same.....thus
1x + 2x = 3x
It's when we are multiplying that the powers change.....thus
1x * 2x = [1 *2] * [x * x ] = 2x^2