Answers:

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Explanation:
For the first expression, we use the rule that
. We add the exponents when multiplying exponentials of the same base. So, 
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In the second expression, we can expand out
into
. The coefficients 2 and 2 multiply to 2*2 = 4 as the final coefficient. The y terms multiply to
. So overall, that's how 
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We use the same idea for the third expression. We'll have two copies of y/4 multiplied together to end up with
. We have
in the numerator and 16 in the denominator.
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For the fourth expression, we can use the rule that
. In other words, if we raised
to some other exponent c, then it's the same as writing
. We multiply the exponents.
The exponents in this case are 3 and 3 which multiply to 9. The 2 is then tacked up front to get 