Exponents and fractions pre-calculus How would I go on about solving this:
${x^4y^7\over x^5y^5}$
When $x = {1\over3}$ and y = ${2\over 9}$
My working out:
Firstly I simplify.-
${xy^2\over x}$
Then substitute
${{{1\over3} * {2\over9}}^2\over{1\over3}}$
Further,
${{{1\over3} * {4\over81}}\over{1\over3}}$
and
${{4\over243} \over{1\over3}}$
since $a/b / c/d = ab * dc$:-
${4\over243} * {3\over1}$
equals
${12\over243}$
Simplified:
${4\over81}$
The correct answer is
${4\over27}$
Can someone help me employ the proper method in solving this problem?
Regards,

The first step is 
$$\frac{y^2}{x}$$
So the answer is
$$
\frac{4/81}{1/3}= \frac{4 \cdot 3}{81} = \frac{4}{27}$$
You just had the extra $x$. Must be an oversight
