$\frac{d}{dx}\left(e^x+e^{-x}\right)$

$\lim_{x\to5}\left(\frac{4x-2b}{3x-15}\right)$

$10c^7\left(5c\right)^2$

$\frac{d}{dx}\left(\frac{\left(9+4x\right)^2}{\left(\sqrt[3]{x^2+1}\right)}\right)$

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

$12\cdot7$

$27a^3x^2+18ax^3$