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Homework Help: Algebra finding 2 variables

  1. Sep 17, 2008 #1
    1. The problem statement, all variables and given/known data
    p=-x^2-2x+100 and p=8x+25, find p and x.


    2. Relevant equations



    3. The attempt at a solution
    -x^2-2x+100=8x+125
    -8x -8x
    -100 -100
    -x^2-10x=-75
    x^2+10x=75
    /10 /10
    1/10x^2+x=75/10 i don't get how to get x alone on one side from here.
     
  2. jcsd
  3. Sep 17, 2008 #2
    Try (Ax^2) + Bx + C =0

    then you know a formula to get x..
     
  4. Sep 17, 2008 #3

    HallsofIvy

    User Avatar
    Science Advisor

    Oh, c'mon! That's a quadratic equation. Factor if you can, or complete the square or use the quadratic formula. Oh, by the way, 125- 100= 25, not 75.
     
  5. Sep 17, 2008 #4
    God I feel stupid. You'd think i'd recognize quadratic equations by now :P. I miswrote 125, supposed to be just 25. Thanks guys!
     
  6. Sep 17, 2008 #5
    No Preblem!!!


    Problem solved :P
     
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