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

$169x^2+260xy+4xy$

$m^2-12m+168$

$\left(r^5+5\right).\left(r^5-5\right)$

$\left(1+\frac{\sin\left(x\right)}{\cos\left(x\right)}\right).\frac{\cos\left(x\right)}{\sin\left(x\right)}$

$100-80e^{-0.4x}$