$\arctan\left(\frac{\left(6.12\cdot10^{-6}\right)}{0.5\cdot10^{-6}}\right)$

$-2x^3+7x^2-3x-12$

$\left(2\right)^3-3\left(2\right)^2+5\left(2\right)-2$

$\frac{64x^6-1}{2x+1}$

$\left(-48\right)-\left(-92\right)+\left(-65\right)+\left(-12\right)$

$9y^3y^3+12y^3$

$-x+1=2x+1$