word problems
At Barney's Takeout Service, the price of an order of french fries is one-half the price of a cheeseburger. An order of five cheeseburgers and three servings of french fries comes to $10.40 (without tax). What is the cost of a cheeseburger?
Let cost of an order of french fries and a burger be F, and B, respectively
Then we get: ------ eq (i)
Also, 5B + 3F = 10.4 ------ eq (ii)
------ Substituting for F in eq (ii)
10B + 3B = 20.8 ------- Multiplying by LCD, 2
13B = 20.8
B, or cost of a cheeseburger =