$-3-9\left|1-3+\left(8+2-1\right)-\left(2-5\right)-13\right|+4-3$

$\left(x+6\right)^2\:\left(x\:+3\right)\left(x\:+5\right)\:-\:2\left(x+\:1\right)\left(x+\:9\right)$

$y''+2y'+2y=0$

$n\left(a+1\right)$

$6x^3+3x^2-15x$

$\frac{\left(3\right)\left(3x^{2}+2x\right)}{4}\cdot\left(\frac{3x^{2}}{4}-2x\right)$

$\left(9a^2+6ab+4ab^2\right)\cdot\left(3a-2b\right)$