SOLUTION: okay so it says factor completely and it is 2x^3+40x^2+220x . I'm so confused about the cubing part of it, I've never seen it before. I've only factored squared numbers. Can you p

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: okay so it says factor completely and it is 2x^3+40x^2+220x . I'm so confused about the cubing part of it, I've never seen it before. I've only factored squared numbers. Can you p      Log On


   

Question 249368: okay so it says factor completely and it is 2x^3+40x^2+220x . I'm so confused about the cubing part of it, I've never seen it before. I've only factored squared numbers. Can you please help me and show work so i can understand it better? thank you! ;)
Found 2 solutions by checkley77, richwmiller:
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
2x^3+40x^2+220x EXTRACT A 2 AND THE X TERM.
2X(X^2+20X+110) NOW FACTOR USING THE QUADRATIC EQUATION BELOW.
x=%28-b%2B-sqrt%28b%5E2-4%2Aa%2Ac%29%29%2F%282%2Aa%29
X=(-20+-SQRT[20^2-4*1*110])/2*1
X=(-20+-SQRT[400-440])/2
X=(-20+-SQRT-40)/2
X=(-20+-6.32455i)/2
X=-20/2+-6.32455i/2
X=-10+-3.16228i ANS.

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
the fact that you have only factored squared numjkbers might have made you think that x^,*x are factors of x^3
2x^3+40x^2+220x
right away you should see that you can factor out 2 and x
so we factor 2x*(x^2+20x+110)
to factor 110 we start
with 2,55
the we see
2,11,5 they are all prime
none of these add up to 20 nor have a difference of 20
so we can't factor all of x^2+20x+110
but we can factor x^2+20x to x(x+20)