$\left(4a^3b-2ab^3\right)\left(2ab^3+4a^3b\right)$

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

$x^2-2\sqrt{3}x=0$

$\left(9xy+8z\right)\left(9xy-8z\right)$

$001.5-87.23$

$\frac{1}{secx}+sinxtanx$

$\left(-4\:+\:5\right)\::\:\left(-\:1\right)\:+\:3\:-\:21\::\:\left(-\:7\right)\::\:3\:\left[-\:11\:.\:\left(-\:2\right)\:-\:19\right]\:$