Waffles

Let the cost of a hamburger = x   and the cost of a carton of milk = y

And we have that

2x  +  1y  = 5

1x +   2y  =  4.60

Using the second equation

x  = 4.60 - 2y

Sub this into the first equation

2 (4.60 - 2y) + 1y  = 5    simplify

9.20 - 4y + 1y = 5

-3y  =  -4.2      divide both sides by -3

y = $ 1.40   =   cost of a carton of milk