Homework Help Forum: maths

Posted by mia on Sunday, October 18, 2009 at 10:35am.

you are at the music store looking for CDs. the store has CDs for $10 and $15. you have $55 to spend. write an equation that represents the different numbers of $10 and $15 CDs you can buy. hmm now.. how do i do this?

• maths - Reiny, Sunday, October 18, 2009 at 10:51am

  your equation will be 10x + 15y = 55 or 2x + 3y = 11 or 2x = 11 - 3y now we want only positive integer values of x and y. clearly x < 6 and y < 4 Furthermore, if y is even, 11 - 3y will be odd, therefore x cannot be an integer. So y has to be odd, and less than 4 Mmmm now, what do you think?

  
  

• maths - mia, Sunday, October 18, 2009 at 11:28am

  thank you very much!! xx (=

  
  

Answer this Question

First Name:
School Subject:
Answer: