Answer:
Boxes sold first week = 104
Boxes sold second week =x+5= 104+5=109
Boxes sold third week = 109 times 2= 218
Step-by-step explanation:
Let x be the number of boxes sold in first week
the girls sold 5 more boxes the second week
So number of boxes sold in second week is x+5
they double the sales of the second week for the third week
So number of boxes sold in third week is 2 (x+5)
Total boxes sold is 431
subtract 15 from both sides
divide by 4 on both sides
Boxes sold first week = 104
Boxes sold second week =x+5= 104+5=109
Boxes sold third week = 104 times 2= 218