Question 71368
what expression raised to the fourth power is {{{81x^12y^8z^16}}}
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Notice some things here ... 
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{{{81 = (3)^4}}} and 
{{{x^12 = (x^3)^4}}} and 
{{{y^8 = (y^2)^4}}} and finally
{{{z^16 = (z^4)^4}}}
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The last three of these (for the letter variables) show the power rule ... that if you raise 
a term with an exponent to a power the result can be found by multiplying the power by 
the exponent. In all of these cases the power 4 multiplies the exponent of the variable,
and the result is that it gets you back to the corresponding term of the original 
problem.
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Now notice the power of 4 is common to every term.  We can pull it and raise the entire 
product to the power of 4. This results in:
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{{{(3*(x^3)*(y^2)*(z^4))^4}}}
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From this you can see that the term that when raised to the fourth power gives you the 
original term in the problem is {{{(3*(x^3)*(y^2)*(z^4))}}}
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Hope this helps you to become a little more familiar with the properties of exponents
and especially how to raise variables with exponents to another power.