$6\left(\frac{b}{b+1}\right)^2+5\left(\frac{b}{b+1}\right)-6=0$

$\frac{4x^5-2x^3-x+6}{x^2+2x-1}$

$\frac{\:2\:cos\:\left(3x\right)}{sin\:\left(2x\right)}+\:\frac{sin\:\left(2x\right)}{cos\:\left(x\right)}=\:\frac{cos\:\left(2x\right)}{sin\:\left(x\right)}$

$40-3x\le10$

$16a^2m^3-24a^3m^2+32a^4$

$\lim_{x\to0}\left(\frac{e^x-e^{-x}}{x^2}\right)$

$5x^2+13x+12=0$