# Solve real world problems with a system of linear equations

by jhduHU
(COACIPC)

A burger place sells burgers (b) for \$4, and fries (f) for \$2. If bob bought six items for a total of \$18, how many did he buy of each?

Solution

A system of linear equations can be used to solve this problem.

Let b be the number of burgers bob bought

Let f be the number of orders he placed for French fries

Then, we can come up with the following two equations

4b + 2f = 18 (equation 1)

b + f = 6 (equation 2)

Solve for b in equation 2. We can do this by subtracting f from both sides of the equation

b + f - f = 6 - f

b = 6 - f

Replace b with 6 - f in equation 1

4 (6 - f) + 2f = 18

4x6 - 4xf + 2f = 18

24 - 4f + 2f = 18

24 - 2f = 18

24 - 18 = 2f

6 = 2f

f = 3

Since b = 6 - f, b = 6 - 3 = 3

Therefore, Bob ordered 3 items each

## Recent Articles 1. ### High School Math Teacher

Jan 20, 20 03:17 PM

Top-notch information for those who want to become a high school math teacher. All important stuff that you need to know before making a move can be found right here on this website.

New math lessons

Your email is safe with us. We will only use it to inform you about new math lessons.

Tough Algebra Word Problems.

If you can solve these problems with no help, you must be a genius! Real Life Math Skills

Learn about investing money, budgeting your money, paying taxes, mortgage loans, and even the math involved in playing baseball.