x3 × x3 × x3 (I'm assuming you mean 3x for that) is equal to 9x^3. x3 × 3 × 3 is equal to 9x. They are not equivalent because one expression has 3x, 3 times, because you are multiplying the 3's together, and adding the x's three times, you get 9x^3. The x's are important since it differentiates between both expressions. 3x × 3 × 3, there is only one x in it, so it is just 9x. Does 9x=9x^3? No.
