$x+7>7$

$\frac{\left(-1\right)^n\cdot\:\:n\cdot\:\left(x+3\right)^n}{4^n}$

$\frac{u^2}{u^2+1}$

$\lim_{x\to+\infty}\left(\frac{e^x-e^{-x}}{2}-x\right)$

$\left(x+-a\right)\left(x+-b\right)$

$\int\left(\frac{1}{\left(21-0.75\cdot q\right)\cdot\left(15-0.25\cdot q\right)}\right)dq$

$2x+x+3y+7y$