$\left(2x^3+4x^2-8x+6\right)+\left(3x^2+9x-10\right)+\left(2x^2+5x-2\right)$

$\lim_{x\to9}\left(\frac{x^2-81}{3x}\right)$

$8y+3-5y-4$

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

$\frac{7}{12}=\frac{x}{84}$

$\int x\cos-1\left(x^2\right)dx$

$\frac{d}{dx}2x^5+4$