57 miles about I'm not positive but I think this is right
Answer:
Step-by-step explanation:
In order to simplify the above expressions we make sure that we get same powers of 10 for both the terms.
So, we multiply and divide the first term with 10
Dividing first term by 10.
Now multiplying it by 10.
Evaluating the new expressions.
Taking 
common factor out.
There is a percentage of 8.333333333333333333333%
15% of 20 gal = 0.15 * 20 gal = 3 gal, so the solution contains 3 gal of salt.
If we add <em>x</em> gal of water to the solution, we end up with (20 + <em>x</em>) gal of solution. We want the new mixture to have a concentration of 10%, or
10% of (20 + <em>x</em>) gal = 0.1 * (20 + <em>x</em>) gal = 2 + 0.1<em>x</em> gal
of salt.
The amount of salt in the tank hasn't changed. Solve for <em>x </em>:
2 + 0.1<em>x</em> = 3
0.1<em>x</em> = 1
<em>x</em> = 10 gal
It would be: 567/18 = 31.5
So, she needs atleast 32 shelves....
