We are given this

write it as the difference of cubes

use the formula for the difference of cubes

Now use the formula for the difference of squares as 

3144/9= 349.33
I used a calculator, but you can also solve this by long division (if a calculator isn’t available)
hope this helps!! :)
Answer:
6 miles
Step-by-step explanation:
A mile is 5280 ft. When you divided 31,680 ft by 5280 ft you get six miles. Hope this helped!
After it is fully simplified, it will be 5x+1-3y