$17+\left(-14\right)+\left(-8\right).\left\{8+\left(-17\right)\right\}$

$x^2+49x+75$

$8\left(x-6\right)=6\left(x-7\right)$

$\left(2x^3+xy\right)^2-\left(2x^3-xy\right)^2$

$81x^5y+99x^3y-60xy$

$f^{\prime}\left(x\right)=-\frac{12x}{\left(x^{2}+1\right)^{2}}$

$\lim_{x\to0}\left(x^{-1}\tan\left(x\right)\right)$