$-20b^2m^2-4b^2n^3+25m^2+5n^3$

$\lim_{x\to0}\left(\frac{2.\sin^2\left(x\right)}{x^2.\left(cos\left(x\right)+1\right)}\right)$

$4y\frac{dy}{dx}+2x=0$

$2\sin\left(a\right)\cos^2\left(a\right)-\sin\left(a\right)=0$

$\lim_{x\to0}\left(\frac{x^3+x^2-x-15}{2x^2-3}\right)$

$y=\frac{\sqrt[4]{\csc\:\left(x\right)}}{\left(x+3\right)^5\left(3x^7-6\right)}$

$\frac{x}{x+4}+\frac{4}{x+4}+2$