malekjammal67 malekjammal67
  • 21-03-2021
  • Mathematics
contestada

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

Respuesta :

adioabiola
adioabiola adioabiola
  • 26-03-2021

Answer:

x = 10; y = 8

Step-by-step 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

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