$\frac{-4x^2-5x-69}{\left(x^2+9\right)\left(x-8\right)}$

$\int\frac{20m}{\left(m+1\right)^2}dx$

$x\cdot y'-y=x^2$

$\int\left(x^3\left(7+x^4\right)^4\right)dx$

$36m^4-36m^2n+9n^2$

$\tan\left(a\right)=\frac{1}{\sin\left(a\right)\cdot\cos\left(a\right)}-\frac{\cos\left(a\right)}{\sin\left(a\right)}$

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