Doublecheck reduction of rational expressions

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SUMMARY

The forum discussion centers on the simplification of the rational expression ##\frac{(\frac{1}{a})^2*b^{-3}}{ab^3}##. The correct final result is ##\frac{1}{a^3b^6}##, as derived through step-by-step simplification. The teacher's provided solution of ##\frac{1}{a^2b^6}## was identified as incorrect due to a typographical error during calculation. Participants emphasized the importance of ensuring both parties are working from the same initial expression to avoid discrepancies in results.

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late347
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Homework Statement


teacher gave me the correct solution which said that the result from him was as follows
##\frac{1}{a^2b^6}##

Homework Equations



original problem was as follows
##\frac{ (\frac{1}{a})^2*b^{-3}}{ ab^3 }##

The Attempt at a Solution



[/B]##\frac{\frac{1}{(a^2)b^3}}{ab^3}##

##= (\frac{1}{a^2b^3}) / (\frac{ab^3}{1})##

##= (\frac{1}{a^2b^3}) * \frac{1}{ab^3}##

##=\frac{1}{a^2b^3} ~~* ~~\frac{1}{a^1b^3}##

##=\frac{1}{a^3b^6}##

notice how there is the denominator ##a^3b^6##
 
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late347 said:

Homework Statement


teacher gave me the correct solution which said that the result from him was as follows
##\frac{1}{a^2b^6}##

Homework Equations



original problem was as follows
##\frac{ (\frac{1}{a})^2*b^{-3}}{ ab^3 }##

The Attempt at a Solution



[/B]##\frac{\frac{1}{(a^2)b^3}}{ab^3}##

##= (\frac{1}{a^2b^3}) / (\frac{ab^3}{1})##

##= (\frac{1}{a^2b^3}) * \frac{1}{ab^3}##

##=\frac{1}{a^2b^3} ~~* ~~\frac{1}{a^1b^3}##

##=\frac{1}{a^3b^6}##

notice how there is the denominator ##a^3b^6##
I agree with your answer, not your teacher's. Make sure that you and the teacher are both starting with the same expression.
 
Mark44 said:
I agree with your answer, not your teacher's. Make sure that you and the teacher are both starting with the same expression.
yep on closer inspection... it looks like my teacher simply used rushed calculation, doing several things at the same time... and he made a typo because of that.

it look like he had a correct mid-result from an earlier calculation but forgot about it.
 

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