$\frac{13x^2-7x-6}{x-1}$

$7x^2+10x+3$

$-\int_1^2\left(cot^2\left(x\right)+1\right)\sec\left(x\right)dx$

$\left(\frac{2}{3}x+\frac{3}{7}\right)\left(\frac{2}{3}x-\frac{1}{5}\right)$

$-\frac{1}{5}m^6\:entre\:\frac{2}{6}m$

$\lim_{x\to infinito}\left(\frac{e^{x^2}-x^2-1}{ln\left(1+x^2\right)-x^2}\right)$

$2x^{-2}-7x^{-1}-15=0$