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anonymous

  • one year ago

Arrg I need help AGAIN

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  1. anonymous
    • one year ago
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    \[x-8=-\sqrt{x ^{2}-8}\]

  2. anonymous
    • one year ago
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    Solution or nah?

  3. UsukiDoll
    • one year ago
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    damn.. one sec.

  4. UsukiDoll
    • one year ago
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    there is a solution... but I'm trying to figure it out... unless we square both sides.. but that - has to be outside so it needs to be something like\[(x-8)^2=-(\sqrt{x ^{2}-8})^2\] then on the right hand side distribute the negative for the left hand side expand

  5. anonymous
    • one year ago
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    ok I'm following you so far

  6. UsukiDoll
    • one year ago
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    \[(x-8)(x-8)=-(x^2-8) \]

  7. UsukiDoll
    • one year ago
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    expand the left = distribute the - on the right

  8. UsukiDoll
    • one year ago
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    can you do that? O_o

  9. anonymous
    • one year ago
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    uhh I'm not sure what it means but i think i could if i know what it was lol

  10. UsukiDoll
    • one year ago
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    use foil for the left hand side of the equation = distribute the negative sign

  11. UsukiDoll
    • one year ago
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    \[(x-8)(x-8)=-(x^2-8) \] I'll do the easy part then you can do the hard one ^_^ \[(x-8)(x-8)=-x^2+8 \]

  12. UsukiDoll
    • one year ago
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    use FOIL method for (x-8)(x-8)

  13. UsukiDoll
    • one year ago
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    in the name of Mathematics we shall expand LOL

  14. anonymous
    • one year ago
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    ohhhh yes i know what to do

  15. UsukiDoll
    • one year ago
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    once that is done.. get the variables to the left and put all numbers to the right

  16. anonymous
    • one year ago
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    \[x^2-16x+64=-x^2+8\] \[-16x=-56\]

  17. UsukiDoll
    • one year ago
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    ok then divide -16 on both sides

  18. anonymous
    • one year ago
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    x=3.5

  19. anonymous
    • one year ago
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    It seems like I did something wrong there though

  20. UsukiDoll
    • one year ago
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    oy keep it in fraction form

  21. anonymous
    • one year ago
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    \[x=3\frac{ 1 }{ 2 }\]

  22. UsukiDoll
    • one year ago
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    something is off. the denominator part is right.. but not the numerator... it's supposed to be x= 9/2

  23. Michele_Laino
    • one year ago
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    hint: we can rewrite the original equation as below: \[\Large \sqrt {{x^2} - 8} = 8 - x\]

  24. UsukiDoll
    • one year ago
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    ok but that would be that we need to square both sides right?

  25. UsukiDoll
    • one year ago
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    \[x^2-8=(8-x)(8-x) \] \[x^2-8=64-8x-8x+x^2\] \[x^2-8=64-16x+x^2\] oh I think I see how it will work now.

  26. UsukiDoll
    • one year ago
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    now try bringing all variables to the left and all numbers to the right

  27. UsukiDoll
    • one year ago
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    hello?

  28. anonymous
    • one year ago
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    I'm here just doing the math

  29. anonymous
    • one year ago
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    16x=72

  30. Michele_Laino
    • one year ago
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    yes! @UsukiDoll

  31. UsukiDoll
    • one year ago
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    ok so now divide 16 from both sides

  32. anonymous
    • one year ago
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    \[x=\frac{ 9 }{ 2 }\]

  33. UsukiDoll
    • one year ago
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    I was trying to get a step by step solution to see how the 9 happen but these sites... I swear they love making a profit off of people for the whole guide. yes! WE GOT IT!

  34. UsukiDoll
    • one year ago
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    whoops ._> I think we should've have \[(x-8)^2=(-\sqrt{x ^{2}-8})^2\] \[(x-8)(x-8)=x^2-8\] \[x^2-16x+64=x^2-8\] allaaalalal and it should be x =9/2

  35. UsukiDoll
    • one year ago
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    -16x=-72 x = 9/2 x.x

  36. anonymous
    • one year ago
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    yeah thats where I'm at XD

  37. UsukiDoll
    • one year ago
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    it's been a while.. now I just refreshed my memory... include all signs when squaring both sides XD

  38. anonymous
    • one year ago
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    lol so I'm having a bit of trouble checking it because its a fraction >.< I hate fractions

  39. UsukiDoll
    • one year ago
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    \[\frac{9}{2}-8=-\sqrt{(\frac{9}{2}) ^{2}-8}\]

  40. UsukiDoll
    • one year ago
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    \[\frac{9}{2}-8=-\sqrt{(\frac{81}{4}) -8}\] then use lcd

  41. anonymous
    • one year ago
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    Ok so I used a decimal instead and i got 9.25=8.25 so I think there is no solution but I'm not sure if I did the math right.

  42. UsukiDoll
    • one year ago
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    don't use decimals. It's a pain

  43. UsukiDoll
    • one year ago
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    \[\frac{9}{2}-\frac{16}{2}=-\sqrt{(\frac{81}{4}) -\frac{32}{4}}\]

  44. UsukiDoll
    • one year ago
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    \[\frac{-7}{2} = -\sqrt{\frac{49}{4}} \]

  45. UsukiDoll
    • one year ago
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    take the square root of 49 and 4.. it's magic :)

  46. anonymous
    • one year ago
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    Oh ok so -7/2=-7/2

  47. UsukiDoll
    • one year ago
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    yes

  48. anonymous
    • one year ago
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    cool thanks

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