The FOIL Method is the order to multiply the two sets of parentheses (first by first term, outer term by outer term, inner term by inner term and last term by last term).
= (x - 6)(x^2 + 4x)
multiply First, Outer, Inner, Last
= (x * x^2) + (x * 4x) + (-6 * x^2) + (-6 * 4x)
multiply in parentheses
= x^3 + 4x^2 - 6x^2 - 24x
combine like terms
= x^3 - 2x^2 - 24x
ANSWER: (B) x^3 - 2x^2 - 24x
Hope this helps! :)