$\left(-18\right)-\left(-10\right)$

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

$\frac{c\left(a+b\right)}{2ab-c};\:a=1$

$-2y+2x+3x$

$25+\left(-5-25\right)-\left(25-5\right)$

$\frac{dy}{dx}=\frac{-y^2}{x\left(x-y\right)}$

$7x^3-2x^2y+5xy^2+\frac{3}{2}y^3+11;\:x=-2;\:y=5$