RESIST
TEMPTATION!! Set up and solve algebraically! Using 32cent, 20cent and 7cent stamps, Rob put $10.08 of postage on a large package. He used twice as many 32cent stamps as 20cent stamps and three times as many 7cent stamps as 32cent stamps. How many of each type of stamp did he use?
Let x = # of 20cent stamps Let y = # of 32cent stamps Let z = # of 7cent stamps So, we have the equation: .20x + .32y + .07z = 10.08 Upon further review, we can say that: the # of 32cent stamps, y = 2x Using substitution: .20x + .32(2x) + .07(6x) = 10.08 <<mult by 100>> 20x + 32(2x) + 7(6x) = 1008 <<simplify each term>> 20x + 64x + 42x = 1008 <<combine like terms>> 126x = 1008 x = 1008/126 x = 8 therefore, Rob used: 8 20cent
stamps
Check your answer in the original problem: .20(8) + .32(16) + .07(48) = 10.08 1.60 + 5.12 + 3.36 = 10.08 TRUE!


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