Three hot dogs and two hamburgers cost $8.00 two hot dogs and three hamburgers cost $8.25. How much does one hot dog cost?
x = cost of one hot dog
y = cost of one hamburger
3x + 2y = 8.00 ---> multiply by 3 ---> 9x + 6y = 24.00
2x + 3y = 8.25 ---> multiply by -2 ---> -4x - 6y = -16.50
adding down the columns 5x = 7.50 ---> x = 1.50
To find y: 3x + 2y = 8.00 ---> 3(1.50) + 2y = 8.00 ---> 4.50 + 2y = 8.00 ---> 2y = 3.50
---> y = 1.75