Question 85492
1. assume variables are positive and multiply
y^6/9 ( y^-6/9 + 4y ^3/9) 

=y^0 + 4y^1

=1+4y
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2. Assume x, y, z are positive #'s use properties of logarithms to write expression log 7 sqrt(x^6 y ^8) / z^7
Comment: Keep in mind this is all base 7.
= log [(x^3y^4)/z^7]

= 3logx + 4logy - 7logz
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3. Find value of x: logx 121/9 = 2 

x^2 = 121/9
x = 11/3
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4. simplify (256 x^4 y)^(1/4) / (81xy^3)^(3/4)

= 4xy^(1/4) / 27x^(3/4)y^(9/4)

= [4/27][x^(1/4)] / y^2

=[4x^(1/4)]/[27y^2]

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Cheers,
Stan H.