<PRE><B>Question 1108713</B>
A delivery truck is transporting boxes of two sizes: large and small.
let L = the wt of the large box
let s = the wt of the small box
 The combined weight of a large box and a small box is 75 pounds.
L + s = 75
or
L = (75-s)
 The truck is transporting 55 large boxes and 70 small boxes.
 If the truck is carrying a total of 4575 pounds in boxes, 
55L + 70s = 4575
simplify, divide by 5
11L + 14s = 915
replace L with (75-s)
11(75-s) + 14s = 915
825 - 11s + 14s = 915
-11s + 14s = 915 - 825
3s = 90
s = 90/3
s = 30 lb is the wt of the small box
then obviously,
75 - 30 = 45 lb is the wt of the large box
:
:
Check this in the total weight equation
55(45) + 70(30) = 4575
 
  </PRE>