Ok So I know you find the GCF first.
5x (x^2 - 14x - 72)
Then _ + _ = -14 & _ x _ = -72
It's 4 and -18 but what do I do from there?
5x (x^2 - 14x - 72)
Then _ + _ = -14 & _ x _ = -72
It's 4 and -18 but what do I do from there?
-
If all you have to do is factor completely you're done. You did GCF to get:
5x(x^2-14x-72)
and that becomes:
5x(x+4)(x-18)
Final answer! :)
Do you know factoring?? It's trial and error. In order to assure yourself that answer is correct, F.O.I.L. (Multiply the first, outer, inner, and last terms then add.)
So the would be x times x + x times -18 + 4 times x + 4 times -18.
Those products would be x^2-18x+4x-72
Combine like terms to get: (x^2 - 14x - 72)
And don't forget the 5x on the outside. Multiply that back into it and you get your original probem.
5x(x^2-14x-72)
and that becomes:
5x(x+4)(x-18)
Final answer! :)
Do you know factoring?? It's trial and error. In order to assure yourself that answer is correct, F.O.I.L. (Multiply the first, outer, inner, and last terms then add.)
So the would be x times x + x times -18 + 4 times x + 4 times -18.
Those products would be x^2-18x+4x-72
Combine like terms to get: (x^2 - 14x - 72)
And don't forget the 5x on the outside. Multiply that back into it and you get your original probem.