4. A stamp collector has some 15¢ stamps and some 20¢ stamps. The number of 15¢ stamps is eight less than three times the number of 20¢ stam

Question

4. A stamp collector has some 15¢ stamps and some 20¢ stamps. The number of 15¢ stamps is eight less than three times the number of 20¢ stamps. The total value is $4. Find the number of each type of stamp in the collection. PLEASE SHOW WORK

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Thiên Hương 3 years 2021-09-04T11:55:14+00:00 1 Answers 14 views 0

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    2021-09-04T11:56:21+00:00

    Answer:

    Step-by-step explanation: Let variable x represent the 15¢ stamps, and variable y represent 20¢ stamps.

    x= 3y-8

    0.15x+0.20y = 4

    Replace x in the second equation by (3y-8)

    0.15(3y-8) + 0.20y = 4

    0.45y – 1.2 +0.20y = 4

    Collect like terms;

    0.45y+0.20y = 4+1.2

    0.65y = 5.2

    Divide both sides by 0.65 to solve for y;

    y= 5.2/0.65

    y = 8

    Replace in equation ” x=3y-8 ” to solve for x;

    x = (3*8) -8

    x=24 – 8

    x = 16

    Therefore, the 15¢ stamps are 16 in number, and the 20¢ stamps are 8 in number.

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