Question

Mike took clothes to the cleaners three times last month.​ First, brought 4 shirts and of slacks and paid ​$11.45. Then brought ​7 shirts, 2 pairs of​ slacks, and 2 sports and paid ​$35.39. ​Finally, brought 5 shirts and 2 sports and paid ​$21.43 . How much was charged for each​ shirt, each pair of​ slacks, and each sports​ coat?

Answer 1

Complete Question:

Mike took clothes to the cleaners three times last month.​ First, brought 4 shirts and 1 pair of slacks and paid ​$11.45. Then brought ​7 shirts, 2 pairs of​ slacks, and 2 sports and paid ​$35.39. ​Finally, brought 5 shirts and 2 sports and paid ​$21.43 . How much was charged for each​ shirt, each pair of​ slacks, and each sports​ coat?

Answer:

The charges

For each Shirt = $1.49

For each pair of slacks = $5.49

For each sports coat = $6.99

Step-by-step explanation:

Let Shirt = a

Let pair of slacks = b

Let sports coat = c

First, brought 4 shirts and 1 pair of slacks and paid ​$11.45

= 4a + b = 11.45 ..........Equation 1

b = 11.45 - 4a

Then brought ​7 shirts, 2 pairs of​ slacks, and 2 sports and paid ​$35.39

= 7a + 2b + 2c = 35.39.........Equation 2

5 shirts and 2 sports and paid ​$21.43

5a + 2c = 21.43............Equation 3

Hence:

4a + b = 11.45 ..........Equation 1

7a + 2b + 2c = 35.39.........Equation 2

Using elimination method

Multiply Equation 2 by the coefficient of b = 1 in Equation 1

Multiply Equation 1 by the coefficient of b = 2 in Equation 2

8a + 2b = 22.9 .......Equation 4

7a + 2b + 2c = 35.39.........Equation 2

Subtracting Equation 2 from Equation 4

= a - 2c = -12.49 ........Equation 5

a = -12.49 + 2c

Subtituting -12.49 + 2c for a in Equation 3

5a + 2c = 21.43............Equation 3

5(-12.49 + 2c) + 2c = 21.43

= -62.45 + 10c + 2c = 21.43

Collecting like terms

10c + 2c = 21.43 + 62.45

12c = 83.88

c = 83.88/12

c = 6.99

5a + 2c = 21.43............Equation 3

Substituting 6.99 for c in Equation 3

5a + 2(6.99) = 21.43

5a + 13.98 = 21.43

5a = 21.43 - 13.98

5a = 7.45

a = 7.45/5

a = 1.49

4a + b = 11.45 ..........Equation 1

Substituting 1.49 for a in Equation 1

4(1.49) + b = 11.45

b = 11.45 - 4(1.49)

b = 11.45 - 5.96

b = 5.49

Therefore, since the charges

For each shirt = a

The charges for each Shirt = $1.49

For each pair of slacks = b

The charges for each pair of slacks = $5.49

For each sports coat = c

The charges for each sports coat = $6.99