$\left(+6\right)\left(-7\right)-\left(5.\right)$

$\left(3xy-6x\right)dx+\left(x^2+1\right)dy=0$

$\log\left(3+x\right)=1-\log\left(4-x\right)$

$\frac{d}{dx}\frac{e^x}{x^2}$

$\left(-7\right)-\left(-9\right)+1$

$\frac{16-2\left(x+5\right)}{x+5}$

$\left(x^2-1\right)^3arctg\left(x^4-2x\right)$