$-15.3+17.2$

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

$\left(4x^3+3x+4\right)+\left(3x^3+2x^2-5\right)-\left(2x^2+x-1\right)$

$x^3+4x^2-9x-36$

$\lim_{x\to\infty}\left(\frac{2}{\sqrt{x^2+9}}\right)$

$\lim_{x\to0}\left(\frac{x}{\left|0\right|}\right)$

$-31>b-11$