Question

Joyce and Haley are running two different bake sales for a school fundraiser. Joyce sold each item for $2 and was given a donation of $7 from a parent. Haley sold each item for $3, but did not have any donations. Who do you expect to make the most money from the bake sale if they sell the same number of items?
solve using the graphing method or the algebraic substitution method.

Answer 1

Joyce: y = 2x + 7

Haley: y = 3x

From looking at these two equations, we can assume that Haley will eventually catch up and pass Joyce because she sells items for $3 whereas Joyce had a head start of $7, but only sells items for $2.

Using substitution, we plug in y = 3x into y in the first equation: 3x = 2x + 7

This leaves us at x = 7.

y = 3(7) or 21.

The point at which Haley's and Joyce's money will be exactly the same is (7, 21). After this point, Haley will have more money.