$x^6-8y^{12}$

$8a^2-24ab+18b^2$

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

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

$-\frac{1}{2}\ln\left(x\right)+\ln\left(x^2+4\right)$

$\left(5^x\right)\left(5^{x-2}\right)\left(5^{x+1}\right)$

$-145-\left(+372\right)$