Question

At Freddy's, three steak burgers and two orders of fries cost $18. Two steak burgers and threeorders of fries cost $15.75. What is the cost for one steak burger? What is the cost of one order of fries?

Answer 1

the cost of one order of fries is $2.25

Explanation:

Let cost of one steak burgers = x

let cost of one order of fries = y

three steak burgers and two orders of fries = 3x + 2y

three steak burgers and two orders of fries cost $18:

3x + 2y = 18 ....equation 1

Two steak burgers and three orders of fries cost $15.75:

2x + 3y = 15.75 ....equation 2

Combine both equations:

3x + 2y = 18 ....equation 1

2x + 3y = 15.75 ....equation 2

Using elimination method:

To elimimnate y, we will multiply equation 1 by 3 and equation 2 by 2.

This will ensure they havethe same coefficent for elimination.

9x + 6y = 54 ....equation 1

4x + 6y = 31.5 ....equation 2

Subtract equation 2 from 1:

9x - 4x + 6y - 6y = 54 - 31.5

5x = 22.5

Divide both sides by 5:

5x/5 = 22.5/5

x = 4.5

Using any equation to get the value for y:

3x + 2y = 18

3(4.5) + 2y = 18

13.5 + 2y = 18

2y = 4.5

y = 4.5/2

y = 2.25

Hence, the cost of one order of fries is $2.25