$6x^2-42x+5$

$\int\left(\frac{81x^8-3}{3x^9-x-2}\right)dx$

$\lim_{x\to1}\left(\sen\left(\frac{\pi}{x^{2}-1}\right)\right)$

$b^2+b-1-8+2+7b+9u+6u+1-7b^2-3b+8b$

$2x\left(x-\sqrt{2}\right)+15\left(\sqrt{2}-x\right)$

$\int\left(3\sec\left(x\right)\tan\left(x\right)\right)dx$

$3-4\cdot\left(2-3\right)\cdot2+\left(4+3+2\right)\cdot\left(-1\right)\cdot2$