$\frac{5}{a-6}+\frac{2}{a-1}=\frac{a^2+4a-15}{\left(a-6\right)\left(a-1\right)}$

$\frac{x^2-6x+2}{x-3}$

$\frac{x^3-3x^2-9x-18}{x^2-9}$

$-8\cdot15+-13\cdot5+-3$

$x^2-10+8$

$\sqrt[3]{\sqrt{x}.\sqrt{x}.\sqrt{x}....\sqrt{x}}\cdot54$

$\frac{y^2}{1-y}dy+\frac{x^2}{x+1}dx=0$