$-y\left(5x^3-7x^2y+xy^2+3y^3\right)$

$3ab-1\cdot\left(3ab-1\right)^2$

$\sqrt[3]{7^6}\cdot2^{12}$

$\frac{3}{4}x^3+2m^2y^3$

$\frac{\tan\left(a\right)}{1+\sec\left(a\right)}+\frac{1+\sec\left(a\right)}{\tan\left(a\right)}$

$z\:=\:2xy$

$3\cdot\left(-4\right)+3\cdot\left(-16\right)$