document.write( "Question 544257: students are having a car wash to raise at least $200.00. they are charging $3.00 a car and $5.00 per van. if they wash three times as many cars as vans how many cars and vans do they need to wash to reach their goal? \n" ); document.write( "

Algebra.Com's Answer #355240 by SwiftAlbatross(13) $\"\"$ $\"About$

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This can be solved by setting up a system of equations with two equations and two variables. The variables, c and v, represent the number of cars and vans respectively. The equations are just the sum of $200 by adding $3 for every car plus $5 for every van, and the conversion of thrice as many cars to vans:\r
\n" ); document.write( "\n" ); document.write( "3c + 5v >= 200
\n" ); document.write( "c = 3v\r
\n" ); document.write( "\n" ); document.write( "Now you can solve because remember if you have as many equations as you do variables, you can solve for all variables. Just use the substitution method:\r
\n" ); document.write( "\n" ); document.write( "3(3v) + 5v >= 200
\n" ); document.write( "9v + 5v >= 200
\n" ); document.write( "14v >= 200
\n" ); document.write( "÷ 14 = ÷ 14
\n" ); document.write( "v >= 14 2/7
\n" ); document.write( "So v = 15, since they must've washed a whole number of vans. The number of cars is 3 times this amount or 15 * 3 = 45. Therefore they washed 45 cars and 15 vans to reach their goal. You can check your answer:
\n" ); document.write( "3*45 + 5*15 >= 200
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