Are variables with different exponents considered like terms?

Answer 1

No, because they can't simply be added together.

For example:

2x and 3x are like terms and can simply be added to be 5x.

If x = 3, 2(3) + 3(3) = 15, which is 5(3)

2x and 3x(squared) can't be added together to make 5x.

If x = 3, 2(3) + 3(9) = 33, which is 11(3).