posted by G on .
Mutiplying a Binomial by a Trinomial
(FOIL) First, Outer, Inner, Last Method
I have tried equation several times. The book says the answer is:
3X 3rd + 8X 2nd - 5X -6
12X 2nd - 6X + 3X 3rd -4
Not sure if i am doing it wrong or if error in the book.
multiply the first two binomials to get
(3x^2 - x - 2)(x+3)
now expand this to get
3x^3 + 9x^2 - x^2 - 3x - 2x - 6
collect like terms and simpify to get the answer that the book gave.