Test 3 Section 3 #19

Let’s say *h* is the number of calories in each hamburger, and *f* is the number of calories in each order of fries. The question gives us enough information to write two equations:

*h* = *f* + 50 (each hamburger has 50 more calories than each order of fries)

2*h* + 3*f* = 1700 (2 hamburgers and 3 orders of fries have a total of 1700 calories)

Let’s solve that system by substitution, since we already have *h* in terms of *f*.

2(*f* + 50) + 3*f* = 1700

2*f* + 100 + 3*f* = 1700

5*f* + 100 = 1700

5*f* = 1600

*f* = 320

The question asks us for *h*, so now we solve for *h*:

*h* = *f* + 50

*h* = 320 + 50

*h* = 370