$-3\left(-3\left(-7+5\right)-2+\left(-3+6\right)\right)-2+20$

$\lim_{x\to1}\left(\frac{x^3+x-2}{x^2-1}\right)$

$y\frac{dy}{dt}=t\left(1+y^2\right)$

$x^2+18x+16$

$\left(7n+8\right)^{2}$

$-2x\cdot4$

$\tan\left(v\right)+\cot\left(v\right)=\frac{2}{\sin\left(2v\right)}$