$\frac{12y^7}{2y^4}$

$\lim x\to\:0\frac{\left(cosx-sinx-1\right)}{2x}$

$\left(-59\right)-\left(-59\right)$

$-12\cdot30$

$12x^2-86x-7$

$\cos\left(\frac{7\pi}{18}\right)\cos\left(\frac{2\pi}{9}\right)+\sin\left(\frac{7\pi}{18}\right)\sin\left(\frac{2\pi}{9}\right)$

$\frac{dy}{dx}=\frac{-4-x}{\left(1+x\right)^2}$