$\left(\frac{2}{5}m^2+\frac{1}{3}mn-\frac{1}{2}n^2\right)\cdot\left(\frac{3}{2}m^2-2n^2-mn\right)$

$6bx^2+3b^2x-4ax-2ab$

$5\:-\:\left(-11\right)$

$\frac{d^2}{dx^2}y^2\cos\left(x\right)+x\tan\left(y\right)$

$-4\left(3-5\right)+8\left(7-2\right)-25\left(9-7\right)$

$\left(a+2\right)\left(a+7\right)$

$x^2-2x=-10$