$\frac{x^{11}}{x^9}$

$a^6-\:3a^4+\:8a^3-4a^2$

$2\left(-1\right)^3-3\left(-1-3\right)+3\left(2\right)-2\left(-3\right)$

$\cos^2\left(90-x\right)\cot\left(x\right)=\sin\left(x\right)\cos\left(x\right)$

$\frac{dy}{dx}=2y-9y^2$

$\frac{\left(-96\right)}{\left(-8\right)}$

$3a^2b;\:a=4;\:b=2$