$\:\left(\sqrt{3+x}-\sqrt{3}\right)\:\left(\sqrt{3+x}+\sqrt{3}\right)$

$\lim_{x\to0.5}\left(\frac{2x^2+5x-3}{2x^2-9x+4}\right)$

$\frac{11}{3}s-\frac{3}{4}t+\frac{2}{3}s-\frac{1}{3}s-\frac{5}{3}s+t+\frac{1}{4}t$

$-16\cdot201$

$\lim_{x\to\infty}\left(1+\frac{y}{x}\right)^{3x}$

$\log_{40}\left(x\right)+\log_{40}\left(x-3\right)=1$

$\lim_{x\to4}\left(\frac{3x+12}{3-\sqrt{2x+1}}\right)$