$-\left(x-1\right)^2+6$

$\left(x+1\right)\left(x+2\right)+\left(x+2\right)\left(x+3\right)-2\left(x+5\right)\left(x-2\right)-2x^2$

$\frac{dy}{dx}\left(y=\sqrt{x+1}\right)$

$2^2+6^2-21+5^2$

$\int\frac{20}{\left(5x-9\right)^2}dx$

$\left(\frac{m}{3}-8n\right)^2$

$\csc^2x+\cot x-1=0$