Sarah begins the year with $100 in her savings account. Each week, she spends $8. Martin begins the year with no money saved, but each week he puts $12
into an account. Let x represent the number of weeks since the beginning of
the year and y represent the total money in the account.
a. Write a linear equation to represent Sarah's total money in her savings
based on the number of weeks that have passed.
b. Write a linear equation to represent Martin's total money in his savings
based on the number of weeks that have passed.
c. Graph both equations on the same first quadrant coordinate plane.
d. At what point do the lines intersect? What is the real-world meaning of
this point?