$\int\frac{x-4}{x^2+7x+6}dx$

$\frac{\sin\left(x\right)\tan\left(x\right)}{1-cos\left(x\right)}=\:\left(1+cos\left(x\right)\right)sec\left(x\right)$

$25\left(x+y\right)^{2}-441\left(x-y\right)^{2}$

$\int_0^{\infty}\frac{59\cos\left(x\right)}{-20\left(x\right)}dx$

$89xy^3\left(11x^6y\right)$

$30\left(3x+4\right)$

$\left(n^{-6}\right)^{-5}$