SOLUTION: (y-7)(4y +12)(y +13)=0 y-7 4y+12 y+13= 0 what do i do next, i'm having a tough time with trinomials?

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: (y-7)(4y +12)(y +13)=0 y-7 4y+12 y+13= 0 what do i do next, i'm having a tough time with trinomials?      Log On


   

Question 339132: (y-7)(4y +12)(y +13)=0
y-7 4y+12 y+13= 0
what do i do next, i'm having a tough time with trinomials?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
You are having a tough time!
When multiplying factors as given in this problem, you can't just put all the terms together as you did, that simply will not work!
Let's see how it goes:
%28y-7%29%284y%2B12%29%28y%2B13%29 You would multiply these three factors two-at-a-time.
Let's take the last two, using the FOIL method to multiply them:
4y%2B12%29%28y%2B13%29+=+4y%5E2%2B52y%2B12y%2B156 Simplify this a bit.
4y%5E2%2B64y%2B156 Now multiply this by the first term (y-7).
%284y%5E2%2B64y%2B156%29%2A%28y-7%29+=+4y%5E3%2B64y%5E2%2B156y-28y%5E2-448y-1092 Simplifying, we get:
highlight%284y%5E3%2B36y%5E2-292y-1092%29