wrappping paper

Question

carlos sold 3 rolls of plain wrapping paper and 1 roll of shiny wrapping paper for a total of 26.00.  Mary sold 12 rolls of plain paper and 8 rolls of shiny wrapping paper for 148.00 What is the cost each of one roll plain wrapping paper and one roll of shiny wrapping paper/

Answer 1

  X = plain  Y = shiny

 

  3X + Y  = 26

 12X + 8Y = 148

 

 

Solving the first equation for Y ----> Y = 26 - 3X

 

Substituting this into the second equation:

 

 12X + 8(26 - 3X) = 148

 

 12X +  208 - 24X = 148

 

  208 -  12X = 148

 

 -12X = -60

 

   X = 5    --->  Y = 26 - 3(5) =  26 - 15 = 11

 

plain rolls cost $5 and shiny rolls cost $11. WE MUST CHECK IT!!!

 

 check: 3 plain and 1 shiny costs 3 x5 + 11 = 15 + 11 = 26

 

           12 plain and 8 shiny costs 12 x 5 + 8 x 11 =  60 + 88 = 148

  

           Answer is verified.

 

Plain rolls cost $5 and shiny rolls cost $11