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Help on exponential equations?

These are the equations that go such as

7^m = 7^n

so m=n

1) (2/3)^4x = (9/4)^x+6

2) 49^x = √(7)

3) 6^x-1 = 10^x

To solve these the bases must be equal, help is greatly appreciated. :)

1 Answer

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  • Juan
    Lv 6
    8 years ago
    Favorite Answer

    1) (2/3)^4x = (9/4)^x+6

    Do you mean (2/3)^4x = (9/4)^(x+6)

    (2/3)^4x = (2/3)^[(-2)(x+6)]

    (2/3)^4x = (2/3)^(-2x-12)

    4x=-2x-12

    6x=-12; x=-2

    2) 49^x = √(7)

    49^x=7^(1/2)

    (7^2)^x=7^(1/2)

    7^(2x)=7^(1/2)

    x=1/4

    3) 6^x-1 = 10^x

    do you mean 6^(x -1) = 10^x

    use the formul; a^x=e^(x*lna)

    e^[(x-1)ln6]=e^(x*ln10)

    x*ln6-ln6=x*ln10

    -ln6=x*ln10-x*ln6

    -ln6=x(ln10-ln6)

    ln6=x(ln6-ln10)

    ln6/(ln6-ln10)=x

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