$-a-b+2b-2c+3a+2c-3b$

$\left(3-x^2\right)\left(2x+1\right)^4$

$\frac{dy}{dx}=-\frac{\left(2x-y\right)}{2y-x}$

$\frac{\cot^2\infty+1}{\cot\infty\sec^2\infty}=\cot\infty$

$\int\frac{3x-1}{\left(x-5\right)\left(x+2\right)}dx$

$\int\left(4t^3y-15t^2-y\right)dt$

$3m\:-10\:\:50$