How do you factor x^3 + 13x^2 + 42x?

1 Answer
Jul 4, 2016

=x(x+6)(x+7)

Explanation:

your expression is ;

= x^3 +13x^2 + 42x

Taking common from this expression :

= x [x^2 + 13x + 42]

Now getting the factors of 42 and seeing if the sum of its factors equals to 13 ( middle value).

By getting its factors (7*6 = 42) we have come to know that 7 + 6 equals to 13.

= x[x^2 + 7x + 6x + 42]

= x[x ( x+7) + 6 (x+7)]

= x[(x+6)(x+7)]