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

$y'\left(x\right)=\left(3\cdot y\right)+x+e^{\left(2\cdot x\right)}$

$x\sqrt{x}^2+2$

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

$m^2\:+\:4m\:=\:27$

$\frac{\sin^2\left(x\right)\left(1-\cos^2\left(x\right)\right)}{\cos^2\left(x\right)}$

$\frac{cos\left(2x\right)-cos\left(6x\right)}{sen\left(2x\right)}$