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Math Help - indices

  1. #1
    Newbie helloworld101's Avatar
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    Question indices

    hi need some assistance in figuring this out can u help me? Here's the question:

    Given that {equ y= ax^b - 6} and that y=10 when x=2 and that y=48 when x=3 find the values of a and b.

    i believe a simultaneous equation will form in order for me to figure out the values of a and b but i dont know how to form it...
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  2. #2
    Senior Member
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    Hi helloworld101

    y= ax^b - 6

    For x = 2 , y = 10 :
    10 = a2^b - 6
    a2^b = 16 .....................(1)

    For x = 3 , y = 48 :
    48 = a3^b - 6
    a3^b = 54 .....................(2)

    Divide the two equations
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  3. #3
    Newbie helloworld101's Avatar
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    i dont understand can u elaborate more plz?
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  4. #4
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    Hi helloworld101

    You can try to divide equation (1) by equation (2) then write here what you've tried
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  5. #5
    Newbie helloworld101's Avatar
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    ok i am not getting through with this sum plz explain more. i tried what u said but i not getting anything. ur help would be immensely appriciated...
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  6. #6
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    \frac{a \cdot 2^b = 16}{a \cdot 3^b = 54}

    \frac{2^b}{3^b} = \frac{16}{54}

    continue ...
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  7. #7
    Newbie helloworld101's Avatar
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    solution to problem

    so this is what i got is the working correct along with the steps
    Attached Files Attached Files
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