$\int18t^5dx$

$\lim_{x\to\infty}\left(\frac{3x-1}{3x+2}\right)^{4x+3}$

$\left(1+\tan\left(a\right)^2\right)\cos\left(a\right)^2=1$

$\int\frac{21}{x^2\sqrt{x^2+9}}dx$

$\lim_{x\to5}\left(\frac{4x^2+19x-5}{x^2+11x-80}\right)$

$25x^2-3=0$

$\left(2x\:+\:x\:2\:\right)\:.\:\left(2x\:-\:x\:2\:\right)$