$3-9\left|1-3+\left(8+2-1\right)-\left(2-5\right)-13\right|+4-3$

$\left(1100-135\right)+\left(680-75\right)+\left(800-12\right)-267$

$\left(-.3\right)\left(-1.16\right)\left(-3\right)$

$\left(b-2\right)\left(b-7\right)$

$x^2-x-1\ge0$

$\lim_{x\to4}\:\frac{\sqrt{1+2x}-3}{\sqrt{x-2-\sqrt{2}}}$

$5a^4b^5+8^a-4a^4b^5-8+3a^4b^5$