$20^9\cdot20^{-7}$

$2\left(x\:+\:4y\right)\:-\:3\left(2y\:+\:9\right)\:$

$y'-2y=e^{2x}$

$\left(3^{2+8b^3}\right)^2$

$\left(5c^2+cd^2\right)\left(5c^2-6d^2\right)$

$\left(2\right)-4x\left(cx+c^2\right)\left(2cx+2c^2\right)+8\left(cx+c^2\right)^2$

$cos\cdot\csc\left(1\right).\tan\left(1\right)$