$\lim_{x\to-\infty}\left(\frac{7x-5}{\sqrt{x^2+1}}\right)$

$-8m-9m+5m$

$603\cdot178$

$\frac{\cos\left(90-x\right)\cos\left(x\right)}{\cot\left(x\right)}=1-\cos\left(x\right)$

$\int\frac{lntx}{e^2}dx$

$5x+13=10x-12$

$arctan\left(tan\left(\frac{3\pi}{4}\right)\right)$