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

$\int\frac{5x^2}{\sqrt{x^2-36}}dx$

$-12-3+0+10+5+15$

$\left(-8\right)\cdot\left(3\right)-\left(+2\right)\left(-7\right)+\left(+5\right)\left(-5\right)$

$\left(2k^3\cdot k\cdot4\right)^3$

$64x^2-81y^2$

$5x^{3}+5y^{2}-5z$