$\left(\:+2\:\right)\:-\:\left(-12\:\:\right)\:=\:$

$\frac{-4x^3+7x^2+x+4}{x^2\cdot\:\left(x+1\right)\cdot\:\left(x-5\right)}$

$\left(3x^2-2\right)\left(3x^2-7\right)$

$9x^2+16x-15=6-4x$

$\cos x\left(\cos x\sin^2x\right)$

$\frac{72x^5-36x^3+6^2}{6x^2}$

$5\left(sin\left(t\right)\frac{dy}{dt}+cos\left(t\right)y\right)=cos\left(t\right)sin^5\left(t\right)$