Aiden says that equivalent expressions always have the same number of terms. Is Aiden correct? If he is, explain why. If he is not correct, give a counterexample.

No. Because for example

4+5 is 9, which has 2 terms (4,5)
BUT
3+5+1 also equals 9, which has 3 terms (3,5,1)

Both equations are equivalent to eachother, but do not have the same amount of terms. This also goes for multiplication.

10x10 is 100, which has 2 terms

BUT

5x10x2 is also 100, which has 3 terms, therefor the answer does not determine the amount of terms in an equation.

Idon’t know this and this isn’t middle school work