$x-9=11$

$\frac{\left(1.5\right)^2}{\left(1.5\right)^{-2}\cdot\left(1.5\right)^4}$

$\frac{d}{dx}b^2x^2-a^2y^2=3a^2b^2$

$\sec\left(a\right)\csc\left(a\right)-\cot\left(a\right)=\tan\left(a\right)$

$\frac{dy}{dx}=e^{4x}y^2+e^{4x}$

$\lim_{x\to0}\left(\frac{\left|x+2\right|-2}{\left|x\right|}\right)$

$\left(+7\right)-\left(-3\right)$