Need some help please

Question

Kristin spent $131 on shirts. Fancy shirts cost $28 and plain shirts cost $15. If she

bought a total of 7 then how many of each kind did she buy?

Answer 1

You want to set up 2 equations using the same 2 unknowns:

Let F=fancy shirts and P=plain shirts

F+P=7

28F + 15P=131

You can solve by substitution or elimination. I will use elimination: Multiply the first equation by -28 giving you

-28F-28P=-196. Line up the 2 equations and add them.

28F+15P=131

-13P=-65 Divide both sides by -13 to solve for P

P=5, so if you have a total of 7 shirts, F=2