$\lim_{x\to\infty}\left(\frac{2x^2+4x-7}{x^3+3x^2-5}\right)$

$\left(\frac{b^4}{-7a^3}\right)^2$

$\left(3x+7\right)\left(7x+6\right)$

$\left(1-2a^2b^3\right)^3$

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

$\frac{dn}{dv}+n=nve^{v+2}$

$\left(x^2-1\right)y''+4xy'+2y$