$6f+2f^2+7f^3+6f+2f^3+7f^2+6f$

$\lim_{x\to2}\left(\frac{\frac{1}{\sqrt{x}}-\frac{1}{\sqrt{2}}}{x-2}\right)$

$( 3 y - 2 ) ^ { \frac { 1 } { 5 } } + 5 = 6$

$6x+9y-2x$

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

$2x\cdot x-6$

$\lim_{x\to0}\left(\frac{e^{x^2}-1}{cos\left(x-1\right)}\right)$