My name is Louise, x^{3} + 9x^{2}  7x  63 Hi Louise,
The only way that I know to factor a cubic is to look for patterns and groupings. The first observation I make with this problem is that 7, 9 and 63 appear and 7 x 9 = 63. Thus Penny
Hello, =(a^{2}  2a + 1)  4b^{2} =(a  1)(a  1)  4b^{2} =(a  1)^{2}  4b^{2} =[(a  1)  2b][(a  1) + 2b] =(a  1  2b)(a  1 + 2b) Hi again Louise, I think the point in both problems is that you break the problem into pieces that you can factor, factor the pieces and then see if you can put them together again. In the problem that you solved you factored a^{2}  2a + 1 as (a  1)^{2} and then saw (a  1)^{2}  4b^{2} as a difference of squares.
In the problem you sent us, x^{3} + 9x^{2}  7x  63, first factor 7x  63, and then factor x^{3} + 9x^{2}, Hence = x^{2}(x + 9) 7(x + 9) = (x^{2}  7)(x + 9)
