$\lim_{x\to\infty}\left(\frac{x-3\sqrt{x}}{\:x-\sqrt{x}}\right)$

$x^2+2xy-y-x\frac{dy}{dx}$

$-\frac{1}{3}ab\:\left(\frac{6}{7}a^{2\:}-\frac{9}{2}b^3+\frac{1}{6}ab\right)$

$8r\:-\:24=-\:34\:+6r$

$\frac{1+2\cos x+\cos^2x+\sin^2x}{\sin x\left(1+\cos x\right)}=2\csc x$

$y8-1$

$\left(9x^4+7y^6\right)^2$