Answer: Choice B) 15x, -x, and 33x
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Step-by-step explanation:
Like terms are when we have the same variable attached to the number. The variable must have the same exponent as well.
For instance, 2x and 3x are like terms since they both have x. Something like 7x and 8x^2 are not like terms because the exponents don't match.
Terms like 17y and 17 are not like terms because the second term doesn't have a y tacked on. If you have nothing but constants, then those are like terms as they all have the same thing in common in that they don't have a variable attached to them.
With all this in mind, we can see that 15x, -x, and 33x is the answer since each have x as part of the variable term. The exponents are all the same (all being 1).