Question

At Billy's Burgers, two bacon cheeseburgers and three orders or curly fries would cost $ 16.45. One order of curly fries and three bacon cheeseburgers would cost $ 16.66. What is the cost of one bacon cheeseburger?
I think I leaned how to do this before but I just can not remember how to do this. Please show me how to do this in steps.

Answer 1

Answer:

Curly fries=$2.29 per order

Bacon=$4.79 per order

Step-by-step explanation:

let b denote bacon and f denote curly fries.

We represent the situations  using inequalities as:

$2b+3f=16.45\ \ \ \ \ ...i\\\\1f+3b=16.66\ \ \ \ \ ...ii$

#we make f the subject of the formula in ii and substitute in i:

$f=16.66-3b\\\\\#substitute \ in \ i\\\\2b+3f=16.45\\\\2b+3(16.66-3b)=16.45\\\\\\2b+49.98-9b=16.45\\\\-7b=-33.53\\\\b=4.79\\\\f=16.66-3\times 4.79\\\\=f=2.29$

Hence, one order of curly fries costs $2.29 and one order of bacon costs $4.79