document.write( "Question 1058097: The​ U-Drive Rent-A-Truck company plans to spend ​$16
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\n" ); document.write( "new vehicles. Each commercial van will cost ​$45000
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\n" ); document.write( "each small truck ​$40000
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\n" ); document.write( "Past experience shows that they need twice as many vans as small trucks. How many of each type of vehicle can they​ buy?
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Algebra.Com's Answer #673181 by solve_for_x(190)\"\" \"About 
You can put this solution on YOUR website!
Let C represent the number of commercial vans, S represent the number of small trucks, and L the number of large trucks.\r
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\n" ); document.write( "\n" ); document.write( "Since the company intends to purchase 310 vehicles, you can write the following equation:\r
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\n" ); document.write( "\n" ); document.write( "(Eq. 1) C + S + L = 310\r
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\n" ); document.write( "\n" ); document.write( "The total cost of the vehicles is:\r
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\n" ); document.write( "\n" ); document.write( "(Eq. 2) 45C + 40S + 80L = 16,000 (all values were divided by 1000 to keep the numbers small)\r
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\n" ); document.write( "\n" ); document.write( "Then, since the number of commercial vans is twice the number of small trucks, you can write:\r
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\n" ); document.write( "\n" ); document.write( "C = 2S\r
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\n" ); document.write( "\n" ); document.write( "Substituting 2S in place of C in Eq. 1 and Eq. 2 gives the following equations:\r
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\n" ); document.write( "\n" ); document.write( "2S + S + L = 310\r
\n" ); document.write( "\n" ); document.write( "45(2S) + 40S + 80L = 16,000\r
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\n" ); document.write( "\n" ); document.write( "or\r
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\n" ); document.write( "\n" ); document.write( "3S + L = 310\r
\n" ); document.write( "\n" ); document.write( "130S + 80L = 16,000\r
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\n" ); document.write( "\n" ); document.write( "Multiplying the first of those equations by 80 gives the following system:\r
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\n" ); document.write( "\n" ); document.write( "240S + 80L = 24,800
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\n" ); document.write( "\n" ); document.write( "Subtracting the second equation from the first leaves:\r
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\n" ); document.write( "\n" ); document.write( "110S = 8800\r
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\n" ); document.write( "\n" ); document.write( "S = 80\r
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\n" ); document.write( "\n" ); document.write( "Then:\r
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\n" ); document.write( "\n" ); document.write( "C = 2S = 2(80) = 160\r
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\n" ); document.write( "\n" ); document.write( "and\r
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\n" ); document.write( "\n" ); document.write( "C + S + L = 310\r
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\n" ); document.write( "\n" ); document.write( "160 + 80 + L = 310\r
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\n" ); document.write( "\n" ); document.write( "L = 310 - 160 - 80\r
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\n" ); document.write( "\n" ); document.write( "Solution: The company should purchase 160 commercial vans, 80 small trucks, and 70 large trucks.\r
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\n" ); document.write( "\n" ); document.write( "Check: The total cost would be:\r
\n" ); document.write( "\n" ); document.write( "45000(160) + 40000(80) + 80000(70) = 16,000,000
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