$\lim_{x\to infinity}\left(846\left(\frac{2}{3}\right)^x\right)-\left(396\left(\frac{1}{3}\right)^x\right)$

$x^2y^2+10xy^3+25y^3$

$\frac{2dv}{dt}+v=10$

$49m^4+140m^2n^2+100n^4$

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

$\frac{\cos\left(x\right)}{1+\sin\left(x\right)}=\frac{\cos\left(x\right)\left(1+\sin\left(x\right)\right)}{1+\sin^2\left(x\right)}$

$6\left(x-7\right)=36$