Question

The cost of 5 dresses and 4 belts is $112. The cost of 3 dresses and 2 belts is $66.

Find the cost of a dress and a belt.

Answer 1

Answer: The cost of dress is $20 and belt is $3

Equation's created:

1) 5d + 4b = 112

2) 3d + 2b = 66

Here 'd' is dress and 'b' is belt

Make 'd' subject:

In equation 1:

⇒ 5d + 4b = 112

⇒ 5d = 112 - 4b

⇒ d = (112 - 4b)/5

In equation 2:

⇒ 3d + 2b = 66

⇒ 3d = 66 - 2b

⇒ d = (66 - 2b)/3

Solve them simultaneously:

(66 - 2b)/3 = (112 - 4b)/5

5(66 - 2b) = 3(112 - 4b)

330 - 10b = 336 - 12b

-10b + 12b = 336 - 330

2b = 6

b = 3

Now find the value of dress:

d = (66 - 2b)/3

= (66 - 2(3))/3

= 20