$\frac{d}{dx}\left(\frac{x^2}{\sqrt{a^2+b^2}}-\frac{x}{a}+\frac{c}{b}\right)$

$48y^2-75$

$\frac{-x^2+3x+7}{\left(x+2\right)^2\left(x^2+x+1\right)}$

$\left(\frac{1}{4}m\:\frac{2}{5}n\right).\left(\frac{1}{4}m-\frac{2}{5}n\right)$

$20-3,35$

$36a^2+36ab^2+9b^4$

$a+3=5a+11$