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What is the value of z in 1/4 raised to the 3z-1 = 16 raised to the z+2 times 64 raised to the z-2

User Dsynkd
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1 Answer

1 vote

Answer:

3/8

Explanation:

In terms of powers of 4, we have ...

(4^-1)^(3z -1) = (4^2)^(z+2)×(4^3)^(z-2)

Taking logarithms base 4*, we have ...

-(3z -1) = 2(z +2) +3(z -2)

-3z +1 = 5z -2 . . . . simplify

3 = 8z . . . . . . . . . . add 3z+2

z = 3/8 . . . . . . . . . .divide by 8

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* This is equivalent to equating exponents of the same base. You're making use of the rules of exponents ...

(a^b)^c = a^(bc)

(a^b)(a^c) = a^(b+c)

1/a = a^-1

and the logarithm relations ...

logb(b^x) = x

log(xy) = log(x) +log(y)

User Marcel Sonderegger
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