$\lim_{x\to\infty}\left(\frac{2^{x+1}-1}{3^x}\right)$

$t^2-6t+10$

$\log\left(x^2-39\right)=1$

$\lim_{x\to\infty}\left(\frac{n^5+4}{\ln\left(n^2+2\right)}\right)$

$\tan\left(a\right)=\frac{\sin\left(2a\right)}{1+\cos\left(2a\right)}$

$3\left(4\:+\:3r\right)$

$41x=22x+912$