For this case, the first thing we must do is define variables. We have then: x: cost of tacos y: cost of enchiladas. We write the system of equations: 2x + 3y = 7.80 3x + 5y = 12.70 Solving the system we have: x = 0.9 $ y = 2 $ Answer: each taco and each enchilada was: x = 0.9 $ y = 2 $