Tim bought 3 hamburgers and 4 hot dogs for $19. John bought 5 hamburgers and 2 hot dogs for $20. How much is one hot dog and one hamburger e

3 b  + 4 h = 19

5 b + 2 h = 20          two unknowns    two equations   solve for b and h   Multiply bottom equation by -2

-10 b -4 h = -40        add to top equation

-7b          =  -21

b = 3                            then use this value for b in oe of the equations to find h     3(3) + 4 h = 19      h = 2.50