# Algebra

Evan washes two types of vehicles. It takes him 30 minutes to wash a car and 40 minutes to wash a truck. He charges \$12 to wash a car and \$15 to wash a truck. In 270 minutes, Evan made \$105 washing cars and trucks. How many trucks did Evan wash?

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1. 30c+40t = 270
12c+15t = 105

now, from the 2nd equation we see that

12c = 105 - 15t, so
30c = 5/2 (105-15t)

plugging that into the 1st equation, we get

5/2(105-15t) + 40t = 270
5(105-15t) + 80t = 540
105-15t+16t=108
t = 3

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2. 👎
2. t=3

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2. 👎

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