$\left(2x+3y\right)^2-\left(2y+1\right)\left(3x-2\right)+2\left(x-y\right)$

$\left(4a^3\right)a^5$

$\lim_{t\to4}\left(3t-4\right)$

$\left(\left(x+y\right)^2+\left(x+y\right)\left(x-y\right)-2\left(x\right)\left(y\right)\right)$

$\lim_{x\to0}\left(\frac{ln\left(2x^2+7\right)}{ln\left(x+3\right)}\right)$

$2x+19>71$

$\left(6\:+\:4x\right)\:x\:\left(6\:-\:4x\right)$