$\lim_{x\to15}\left(\frac{\sqrt[2]{x-1}-\sqrt[2]{14}}{\sqrt[2]{x+2}-\sqrt[2]{17}}\right)$

$-125a^9b^{15}-1$

$\frac{4}{x}+\frac{x}{x+3}=\frac{9}{x^2+3x}$

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

$3xy^2z-4xz^2$

$f\left(x\right)=\frac{x^2-14x+49}{x^2-10x+2}$

$\log_m\left(x\right)+\log_m\left(y\right)$