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eli123 Group Title

factor 21x^2-49x-9x-21

  • one year ago
  • one year ago

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  1. eli123 Group Title
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    idk how i got 7x(3x-7) 3(3x-7) and i know its wrong

    • one year ago
  2. hartnn Group Title
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    is the original problem 21x^2-58x-21 ?

    • one year ago
  3. eli123 Group Title
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    no

    • one year ago
  4. eli123 Group Title
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    • one year ago
  5. hartnn Group Title
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    right,so thats 21x^2-40x-21=0 right ?

    • one year ago
  6. eli123 Group Title
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    yeah and then the product of 21 and -21 is -441 and then 40 so the two numbers are -49 and 9

    • one year ago
  7. hartnn Group Title
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    that is correct, see above u have written -49x - 9x instead of what u got now as -49x+9x

    • one year ago
  8. eli123 Group Title
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    oooh i see wow

    • one year ago
  9. hartnn Group Title
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    now whats common from first 2 terms in 21x^2-49x-9x-21 =0?

    • one year ago
  10. eli123 Group Title
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    7x

    • one year ago
  11. eli123 Group Title
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    i got the answer :P -3/7 and 7/3

    • one year ago
  12. hartnn Group Title
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    yup, correct.

    • one year ago
  13. eli123 Group Title
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    im having problems with another equation

    • one year ago
  14. hartnn Group Title
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    which ?

    • one year ago
  15. eli123 Group Title
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    • one year ago
  16. eli123 Group Title
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    i got to the point 9 + or - sqrt of 1 all over 4

    • one year ago
  17. hartnn Group Title
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    9 from where ?

    • one year ago
  18. hartnn Group Title
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    Compare your quadratic equation with \(ax^2+bx+c=0\) find a,b,c then the two rots of x are: \(\huge{x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}}\)

    • one year ago
  19. eli123 Group Title
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    yeah b is 9

    • one year ago
  20. hartnn Group Title
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    nopes, b is -4

    • one year ago
  21. eli123 Group Title
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    oh wait nooo i gave you the wrong equation! no wonder

    • one year ago
  22. hartnn Group Title
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    lol :P

    • one year ago
  23. eli123 Group Title
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    • one year ago
  24. hartnn Group Title
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    still b is -9

    • one year ago
  25. eli123 Group Title
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    but in that equation it says -b so -(-9) is 9

    • one year ago
  26. eli123 Group Title
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    inside i did put put -9^2 = 81

    • one year ago
  27. hartnn Group Title
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    yes, u are correct \(\huge\frac{9 \pm \sqrt{1}}{4}=\frac{10}{4},\frac{8}{4}\)

    • one year ago
  28. eli123 Group Title
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    wait you are just adding and subtracting the 1?

    • one year ago
  29. eli123 Group Title
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    obviously lol never mind i feel stupid

    • one year ago
  30. hartnn Group Title
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    got it now ?

    • one year ago
  31. eli123 Group Title
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    yes, it was a stupid moment :P

    • one year ago
  32. eli123 Group Title
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    ok i did another one and i got 4+-sqrt of 28 all over 2 @hartnn

    • one year ago
  33. hartnn Group Title
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    question ?

    • one year ago
  34. eli123 Group Title
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    its the first one that sent you

    • one year ago
  35. eli123 Group Title
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    • one year ago
  36. hartnn Group Title
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    thats correct :)

    • one year ago
  37. eli123 Group Title
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    but how do i factor it?

    • one year ago
  38. hartnn Group Title
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    do u want to factor or do u want to use quadratic formula? anyways its not factorable....

    • one year ago
  39. eli123 Group Title
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    so what would be the answer?

    • one year ago
  40. eli123 Group Title
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    i cant simplify it?

    • one year ago
  41. hartnn Group Title
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    all u can do is \(2 \pm \sqrt7\)

    • one year ago
  42. hartnn Group Title
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    \(\sqrt{28}=2\sqrt7\)

    • one year ago
  43. eli123 Group Title
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    how does that equal to that

    • one year ago
  44. hartnn Group Title
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    \(\sqrt{28}=\sqrt{7*4}=\sqrt{7}\sqrt{4}=2\sqrt{7}\)

    • one year ago
  45. eli123 Group Title
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    got it

    • one year ago
  46. eli123 Group Title
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    you are the best!

    • one year ago
  47. hartnn Group Title
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    lol. glad to hear that :) u too are awesome ;)

    • one year ago
  48. eli123 Group Title
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    lol thank you, well i gotta keep doing this stupid hw

    • one year ago
  49. hartnn Group Title
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    best of luck for that.

    • one year ago
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