Yumi spent $34.15 buying stamps. The number of 56-cent stamps she bought was 10 less than 4 times the number of 41-cent stamps. How many of each did she buy?

Solution:

Let "a" be the number of 56 cent stamps

Let "b" be the number of 41 cent stamps

The number of 56-cent stamps she bought was 10 less than 4 times the number of 41-cent stamps

number of 56-cent stamps = 4 times the number of 41-cent stamps - 10

a = 4b - 10 -------- eqn 1

Yumi spent $34.15 buying stamps

Therefore,

56a + 41b = 3415 ------- eqn 2

Substitute eqn 1 in eqn 2

56(4b - 10) + 41b = 3415

224b - 560 + 41b = 3415

265b = 3975

Substitute b = 15 in eqn 1

a = 4(15) - 10

a = 60 - 10

Thus number of 56 cent stamps is 50 and number of 41 cent stamps is 15

y=x+9

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step-by-step explanation: