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    You need to solve for x

    I got x = 11

    The textbook got x = 6 they change the x-5 bit into an x+5, I dont know why :/

    Help is appreciated thanks.
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    Since all of these are powers of 3, it's like doing simple powers where, for exampe. x ^ 4 / x ^ 3 = x ^ (4 - 3)

    So, on the lhs, subtract the two powers and watch your signs, put it equal to 17 and solve.

    I think (I'm guessing because i can't see your working) where you've gone wrong is with the 3x - (x-5) - that negative sign before the bracket will change the sign inside.
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    387420489 / 3 = 129140163

    How tf you got 11 you would have to explain to me,

    but its 3^(3x6) = 3^18 = 387420489
    3^ (6-5) = 3^1 = 3
    3^17 = 129140163
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    (Original post by tomnelson_)
    387420489 / 3 = 129140163

    How tf you got 11 you would have to explain to me,

    but its 3^(3x6) = 3^18 = 387420489
    3^ (6-5) = 3^1 = 3
    3^17 = 129140163
    Urrm you forgot the bit that said "Solve for X" in the desc
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    (Original post by phys981)
    Since all of these are powers of 3, it's like doing simple powers where, for exampe. x ^ 4 / x ^ 3 = x ^ (4 - 3)

    So, on the lhs, subtract the two powers and watch your signs, put it equal to 17 and solve.

    I think (I'm guessing because i can't see your working) where you've gone wrong is with the 3x - (x-5) - that negative sign before the bracket will change the sign inside.
    Cheers i see it now thanks
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    (Original post by lollolokjob)
    Urrm you forgot the bit that said "Solve for X" in the desc
    because its six....
 
 
 
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