Question

if the weight of a package is multiplied by 5/7 the result is 40.5 pounds. Find the weight of the package.

Answer 1

ok let x represent the weight of the package. So the package multiplied by 5/7 is 5/7x. 

=> 5/7x = 40.5lbs 
=> 40 1/2 * 7/5 = x 
=> 81/2 * 7/5 = x 
=> 567/10 = x 
=> 56.7 lbs = x 

OR 

let 1 equal the weight of the package 

5/7 = 40.5 lbs 
1 = x 

=> 40.5 divided by 5/7 
=> 81/2 * 7/5 
=> 567/10 
=> 56.7 lbs

Answer 2

first convert 5/7 into a decimal
5 divided by 7= .71

and if the total weight was multiplied by .71 (same as 5/7) to get the original weight you must do the opposite operation which is division.
40.5 divided by .71= 57.04

That's how I got my answer...