Question

3. A chef bought $17.01 worth of ribs and chicken. Ribs cost 1.89 per pound and chicken costs 0.90 per pound. The equation 0.9c + 1.89r = 17.01 represents the relationship between the quantities in this situation. Show that each of the following equations is equivalent to. 0.9c + 1.89r = 17.01 Then, explain when it might be helpful to write the equation in these forms.

A. c = 18.9 - 2.1r
B. r = - 10/21 c + 9

Answer 1

Answer:. r = - 10/21 c + 9

Explanation:

Answer 2

• See below

Explanation:

Given equation:

• 0.9c + 1.89r = 17.01

Make c the subject:

• 0.9c = 17.01 - 1.89r

Divide all terms by 0.9:

• c = 17.01/0.9 - 1.89r / 0.9
• c = 18.9 - 2.1r

Now make r the subject:

• 1.89r = 17.01 - 0.9c

Divide all terms by 1.89:

• r = 17.01/1.89 - 0.9c/1.89
• r = 9 - 1/2.1c
• r = 9 - 10/21c
• r = - 10/21c + 9

Confirmed that both equations are equivalent with the initial one.

These are helpful when finding one of the variables if the value of another variable is given.