$\left(9-5\right)-\left(3-1\right)$

$68.1\cdot11.222$

$\cos\left(b\right)-1=0$

$\left(x^2y^2-6\right)\left(x^2y^2+8\right)$

$\frac{d^2}{dx^2}\left(2x^3+5x^2+2\right)$

$3\left(1.2\right)^4-3\left(1.2\right)^3-\left(1.2\right)^2+3\left(1.2\right)-1\:$

$\sqrt[3]{64a^5b^6}-\sqrt{64a^6b^5}$