$\left(7x\right)^2+\left(9y\right)^2$

$\frac{x^5-10x^3+2x-20}{x+2}$

$2ab\cdot3c$

$\left(-3\right)\cdot\left(-6\right)-\left|\left(-4-\frac{10}{2}\right)-\left(-4\right)\right|$

$4x^2-3x-1$

$\frac{\sin\frac{2}{x}}{\frac{1}{x}}$

$8\left(-3+2+5\right)+5\left(-8+9-3\right)\left|6\left(-9\right)\right|$