$9\left(13-x\right)-4x=5\left(21-2x\right)+9x$

$\lim\:_{x\to\:1}\left(2^x+x\right)^{\frac{1}{x}}+\lim\:_{x\to\:0}\left(\frac{cos\left(x-1\right)}{x}\right)$

$7\sqrt{xy}$

$7z+10-z=8z-2$

$\left(x+y\left(x\right)+1\right)\cdot y'\left(x\right)=1$

$\left(-2x\right)\left(-2x\right)\left(-2x\right)$

$\left(x^2-4x+3\right)\:\left(x-1\right)$