Write an equation that represents the number of sheets of paper, y , she will have after x months

Question

Allison uses 6 sheets of paper per day for her homework and classwork. She started the month with 72 sheets of paper. Let y represent the number of pieces of paper that she has, and let x represent the number of school days that have passed in the month.

Answer 1

Alex, if she starts with 72 sheets, whatever she uses will be subtracted from that.

 

After 2 days, she'll have used 6 x 2 sheets and have 72 - 6 x 2 = 60 sheets, so y will be 60.  After x days, she'll have 72 - 6x sheets.

 

We put y in front, so our equation is y = 72 - 6x. We also usually put terms with variables first, so we could also write y = -6x + 72.

 

Hope this helps!