Answer
7$x^{4}$
Work Step by Step
You have the expression $\frac{21x^3}{3x^-1}$.Simplify the expression:
(7$\div$3)($x^{3-(-1)}$) -divide 21 and 3 to get 7 and then subtract the exponents because you are dividing powers with the same base-
=7$x^{4}$
