Question 572262
"Kristin spent $131 on shirts.  Fancy shirts cost $28 and plain shirts cost $15" ___ 28f + 15p = 131


"she bought a total of 7" ___ f + p = 7 ___ p = 7 - f


substituting the equivalent value of p ___ 28f + 15(7 - f) = 131


28f + 105 - 15f = 131 ___ 13f = 26


solve for f , then substitute back to find p