$\frac{1}{2}x-\{\frac{3}{4}x-2y+\left(2x-\frac{2}{3}y-[-x+\frac{1}{4}y-\left(-x-y\right)]\right)\}$

$g\left(x\right)\:=\frac{1}{x^7}+\frac{2}{x^9}+x+1$

$\left(x+3\right)\left(x^2-3x+9\right)-27$

$\int\frac{4x^3-6x^2-8x+1}{2x-4}dx$

$1-7r-5+4r-3r-5$

$\int6xe^{x^2}dx$

$\int\frac{x^3+3x^2-2x+7}{4}dx$