$4-m^2$

$\left(3.2\right).\left(-6\right)$

$\frac{dy}{dx}=8xe^{-y}$

$\left(7m^6+6\right)\left(7m^6-6\right)$

$5m-6x-9z+11v+7m-9x-11z+8v+4m-8z+8x+14v$

$\frac{-a+3}{-\left(a-2\right)}+\frac{-1}{-\left(a+3\right)}-\frac{-1}{-\left(a+3\right)}=1$

$\sec^2x\left(1-sin^2x\right)$