$\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)+6$

$3\left(2n+1\right)-\left(-6n-11\right)$

$\left(t^{2}+2t-5\right)\left(3t^{2}-t+2\right)$

$\frac{\tan x-\sin x}{\tan x\sin x}=\frac{1-\cos x}{\sin x}$

$x^2+20x-9$

$\int\left(7e^{-20x}\right)dx$

$2x+1\ge5$