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:

hf + 50 (each hamburger has 50 more calories than each order of fries)
2h + 3f = 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) + 3f = 1700
2f + 100 + 3f = 1700
5f + 100 = 1700
5f = 1600
f = 320

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

hf + 50
h = 320 + 50
h = 370