$2a^{3}b+4a^{3}c-6a^{2}d$

$\frac{20x^3+15x^2-10x}{x+1}$

$9a^2-6ab+6ab-4b^2$

$-5x^{\left(6\right)}\left(x^{\left(6\right)}+13\right)^{\left(5\right)}\left(x^{\left(7\right)}-11\right)^{\left(4\right)}\left(2x+9\right)^{\left(3\right)}=0$

$\int x^{\left(3\right)}\sqrt{\left(\left(2x\right)^{\left(4\right)}+\:3\right)}dx$

$\int\sqrt{mn+nx}dx$

$\left(x+y\right)dy-\left(-x+y\right)dx=0$