$4+\left(-243\right)-4$

$\frac{1}{8a\left(3\right)}+8\left(3\right)$

$\lim_{x\to-\infty}\left(\frac{2e^x}{e^x-5}\right)$

$m2+19m-20$

$\lim_{x\to-4}\left(\frac{x^2-16}{x^3-64}\right)$

$8y^2z^4+2y^2z^4+5y^2z^4$

$\left(9x+6\right)\left(9x+3\right)$