$-x^2y-\left(-3x^2.7y\right)+\left(16x^2y^3z:4.y^2z\right)$

$\left(6x^2+2x+8\right)-\left(3x^2-4x+5\right)$

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

$x^2-x-1\:\:\:\:\:+\:\:\:\:\:\:\:\:x^2-x-1\:\:\:\:\:$

$17-2w-3+70-7w$

$\int\left(2x\right)\sqrt{x^2+25}dx$

$f\left(x\right)=\left(x^{\frac{2}{5}}+12\right)^2$