Algebra 1
posted by Monica .
A girl scout troop sold cookies. If the girls sold 5 more boxes the second week than they did the first, and if they doubled the sales of the second week for the third week to sell a total of 431 boxes of cookies, how many did they sell each week?

Say x is the number of boxes sold in week 1, then:
Boxes in week 1: x
Boxes in week 2: x + 5
Boxes in week 3: 2x + 10
Total boxes = 4x + 15
4x + 15 = 431
x = 104
So in week 1 there was sold
x = 104
in week 2:
x + 5 = 109
in week 3:
2x + 10 = 218 
Yea i juss did the problem on paper an got the same answer. Thank yu :)