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 cookies, how many did they sell each week ?

Respuesta :

Answer:

wk. 1 : 104, wk. 2 : 109, wk.3 : 218

Step-by-step explanation:

x = 1st week, y = 2nd week, z = 3rd week

x + y + z = 431

y = x + 5.........y - 5 = x

z = 2y

(y - 5) + y + 2y = 431

4y - 5 = 431

4y = 431 + 5

4y = 436

y = 436/4

y = 109 <==== week 2

z = 2y

z = 2(109)

z = 218 <==== week 3

x = y - 5

x = 109 - 5

x = 104 <==== week 1