$\frac{dy}{dx}\left(\frac{\left(x+1\right)\left(x-6\right)}{\left(x-1\right)\left(x+6\right)}\right)$

$\lim_{x\to-3}\left(x^2-3x+2\cdot x-3\right)$

$2\left(-3\right)\left(4\right)\left(-5\right)\left(6\right)$

$x^2+16x+1=0$

$35x^2+12x+1$

$\lim_{x\to0}\left(\frac{4e^{6-2x}-f''\left(x^2\right)}{f'\left(x\right)+1}\right)$

$-2u-5c+3+6u-c$