21. FUNDRAISING Yvonne and her friends held a bake sale to benefit a shelter for homeless
people. The friends sold 22 cakes on the first day and 15 cakes on the second day of the
bake sale. They collected $88 on the first day and $60 on the second day. Let xrepresent
the number of cakes sold and y represent the amount of money made. Find the slope of the
line that would pass through the points given.