Simplify the following, giving your answer in index form:
$\frac{\left(n^7r^2\right)^4}{\left(n^4r\right)^4}$(n7r2)4(n4r)4
Simplify $\frac{9x^5+8x^4}{x}$9x5+8x4x.
Simplify $\frac{40x^3-48x^2+32}{8}$40x3−48x2+328.
Simplify $\frac{15x^4-24x^3-21x^2+12x}{3x}$15x4−24x3−21x2+12x3x.