$a^4b-2a^3b+a^3b^2-2a^2b^2$

$18+35+27+50$

$\lim_{x\to1}\left(\frac{ln\:x}{10x-x^2-9}\right)$

$\left(c+4\right)a^{c+3}b^{d+4}$

$\lim_{x\to+\infty}\left(\frac{3x^2-5}{x+2}\right)$

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

$\frac{dy}{dx}\left(x^2+y^2\right)$