sleepingknights789 sleepingknights789

02-04-2021
Mathematics

contestada

David bought 3 DVDs for 4 books for $40 at a yard sale. Anna bought 1 DVD and 6 books for $18. How much did each DVD and book cost?

Respuesta :

clarch19 clarch19

02-04-2021

Answer:

dvd cost $12 each

book cost $1 each

Step-by-step explanation:

3d + 4b = 40

d + 6b = 18

substitution method:

d = 18-6b

3(18-6b) + 4b = 40

54 - 18b + 4b = 40

-14b = -14

b = $1

d + 6 = 18

d = $12

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