$x^2+y=4$

$19\times\left(28-27\right)+15$

$y=x\left(x+5\right)\left(x+2\right)$

$12m^2n^3\:+\:8\:m^4\:n^2\:-\:4mn$

$4ab^2+7ab^2+ab^2$

$\left(1-2sin^2\left(x\right)\right)\left(1+tan^2\left(x\right)\right)$

$\frac{1}{\sin\left(x\right)\cdot\cos\left(x\right)}-\cot\left(x\right)=\tan\left(x\right)$