Simplify the following, giving your answer in index form:

$\frac{u^{13}}{u^2}$u13u2

$a^5\div a^3$a5÷a3

Convert the following to a fraction and simplify using the Index Laws: $x^9\div\left(3x\right)^2$x9÷(3x)2

$\frac{t^7r^8}{t^5r^4}$t7r8t5r4