SOLUTION: I need to create and solve an equation, but I don't know how. The problem is: A moving company weighs 20 boxes you have packed that contain either books or clothes and says that

Algebra ->  Linear-equations -> SOLUTION: I need to create and solve an equation, but I don't know how. The problem is: A moving company weighs 20 boxes you have packed that contain either books or clothes and says that       Log On


   

Question 493005: I need to create and solve an equation, but I don't know how.
The problem is: A moving company weighs 20 boxes you have packed that contain either books or clothes and says that the total weight is 404 pounds. You know that a box of books weighs 40 pounds and a box of clothes weighs 7 pounds. How many boxes of books and how many of clothes did you pack?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let B = the number of boxes of books and their total weight will then be B*(40lbs).
The number of boxes of clothes will be (20-B) and their total weight will be (20-B)*(7lbs). The sum of the weights of all of these boxes will be 404lbs.
Let's write the equation that models this situation:
B*(40)+(20-B)*(7) = 404 Simplify this and solve for B.
40B+140-7B = 404 Subtract 140 from both sides.
40B-7B = 264
33B = 264 Divide both sides by 33.
B = 8
and 20-B = 12.
There were 8 boxes of books and 12 boxes of clothes.