Question

The cost of 3 DVDs and 4 CDs £62.00. the cost of 4 DVDs and 3 CDs is £64.00.find the cost of each.

hellllp

Answer 1

x = 10; y = 8

Explanation:

Let

DVDs = x

CDs = y

3x + 4y = 62 (1)

4x + 3y = 64 (2)

Multiply (1) by 4 and (2) by 3 to eliminate x

12x + 16y = 248 (3)

12x + 9y = 192 (4)

Subtract (4) from (3)

16y - 9y = 248 - 192

7y = 56

y = 56/7

y = 8

Substitute y = 8 into (1)

3x + 4y = 62

3x + 4(8) = 62

3x + 32 = 62

3x = 62 - 32

3x = 30

x = 30/3

x = 10

x = 10; y = 8