$7-2x>-3$

$\sqrt{\sqrt{\frac{256}{2401}}}-4^{-2}.\frac{2^2}{4^3}.4^6-\left(\frac{1}{2}\right)^{-3}$

$15x\left(-15\right)$

$\lim_{x\to0}\left(\frac{x+x^2}{3-4x^2}\right)$

$\int\frac{6x}{\sqrt{x^2-16}}dx$

$2x+5y+7x-y$

$-9\left(\sin\left(x\right)\right)^{\frac{-3}{2}}\left(\cos\left(x\right)\right)$