text: First, we notice that there is a common factor of 2a² in each term, so we pull that out of the equation to get:\n\n2a² (a² - 9)\n\nThen we can see that the part in the brackets is actually a difference of squares. So we use the difference of squares rule\n(x² - y²) = (x-y)(x+y) to factor the part inside the brackets. We obtain:\n\n2a² (a - 3)(a + 3)