In this question I do not see how x^5 becomes an x^4 in the second step.
I understand that x^2 = u-4 and that x^2 * x^2 = x^4, but if we started with x^5 and we now have x^4, were is the extra x?
In this question I do not see how x^5 becomes an x^4 in the second step.
I understand that x^2 = u-4 and that x^2 * x^2 = x^4, but if we started with x^5 and we now have x^4, were is the extra x?