$4x+2ax-5x+7ax+x$

$\left(a-6b\right)^2$

$\left(4x^4-\:5x^2+\:8x\:-\:10\right)\::\:\left(x^2+\:2\right)$

$\cot\left(x\right)\cdot\sin\left(x\right)+\tan\left(x\right)=\cos\left(x\right)+1$

$4^{x+3}=\left(\frac{1}{2}\right)^x$

$\frac{dy}{dx}=\frac{\left(yln\left(x^y\right)\right)}{x}$

$4a^2-18$