$x^4-29x^2+140$

$x+2y+z=1$

$\int\frac{1}{m+m^3}dm$

$\frac{dy}{dx}=\frac{x^3}{y}$

$\lim_{x\to\infty}\left(2ln\left(x^2+1\right)-4ln\left(x+1\right)\right)$

$\left(5a+9\right)\left(\frac{1}{2}b-6\right)$

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