$\frac{\left(tan^2x-1\right)}{sinx+cosx}=\frac{\left(sinx-cosx\right)}{cos^2x}$

$\left(2xy^3-y+2\right)dx+\left(3x^2y^2-x+7\right)dy=0$

$10.5\cdot4$

$-36\left|-12\right|$

$\left(9-6y\right)\left(9+6y\right)$

$\left(24-2x^2\right)^2$

$sen\left(240\right)\cos\left(240\right)\tan\left(240\right)$