$4\cdot\left(-11\right)$

$\left(x+7\right)\left(x^2-3x+2\right)$

$dy=\frac{-x}{\sqrt{4-x^2}}dx$

$\int\frac{5x^2-x-1}{x^2\left(2x+1\right)}dx$

$\left(\frac{1}{2}x^{2}-\frac{1}{3}xy+\frac{1}{4}y^{2}\right)\cdot\left(\frac{2}{3}x-\frac{3}{2}y\right)$

$-2\cot\left(x\right)\cdot\csc^2\left(x\right)$

$9x^2-42x+50$