$15\left(2x^2-5x+7\right)-8\left(\left(x-2\right)\left(x-4\right)\right)$

$\int3x\cos\left(\frac{x}{3}\right)dx$

$\frac{\left(4x^2-3x^3+9x\right)}{3x}$

$\left(\:a-\:8\right)\cdot\:\left(\:a\:+\:6\:\right)\infty$

$\left(x\cdot cos\left(x\right)-\sin\left(x\right)\right)^2$

$9x^2-20x+12$

$\left(3x^3-2x^2+5x-6\right)-\left(3-6x+3x^2\right)$