$\left(2x-9\right)^2-\left(2x-1\right)^2$

$x^2\cdot lnx=\frac{\left(y+1\right)^2\cdot\frac{dy}{dx}}{y}$

$35r^4s^7+105r^8s^7+7r^6s^6$

$\lim_{x\to0}\left(\frac{4\left|sin\left(x\right)\right|}{\left|x-4\right|+\left|x+4\right|}\right)$

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

$\left(-5x^2\right)\left(-4x^3\right)$

$8.5m+2.2+1+8.9m$