document.write( "Question 320038: A bank robber holds up a bank and speeds away on the freeway at 80 miles per hour. Thirty minutes later, police officers, having gotten a description from people at the bank, take off in pursuit at 90 miles per hour. How long will the police have to drive to catch up, and how far from the bank will they catch the robber? \n" ); document.write( "

Algebra.Com's Answer #229191 by Edwin McCravy(20065) $\"\"$ $\"About$

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A bank robber holds up a bank and speeds away on the freeway at 80 miles per hour. Thirty minutes later, police officers, having gotten a description from people at the bank, take off in pursuit at 90 miles per hour. How long will the police have to drive to catch up, and how far from the bank will they catch the robber?
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document.write( "Make this chart\r\n" );
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document.write( "          DISTANCE       RATE       TIME\r\n" );
document.write( "Robber\r\n" );
document.write( "Police\r\n" );
document.write( "\r\n" );
document.write( "Let the police's time be x. So fill in x for the Police's time.\r\n" );
document.write( "\r\n" );
document.write( "          DISTANCE       RATE       TIME\r\n" );
document.write( "Robber                \r\n" );
document.write( "Police                                x\r\n" );
document.write( "\r\n" );
document.write( "Fill in the two speeds:\r\n" );
document.write( "\r\n" );
document.write( "          DISTANCE       RATE       TIME\r\n" );
document.write( "Robber                    80 \r\n" );
document.write( "Police                    90          x\r\n" );
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document.write( "The robber has a 30 minute headstart, so the robber's time is \r\n" );
document.write( " hour more than the police's time of x hours, so fill\r\n" );
document.write( "in x+ for the Robber's time:\r\n" );
document.write( "\r\n" );
document.write( "          DISTANCE       RATE       TIME\r\n" );
document.write( "Robber                    80         x+\r\n" );
document.write( "Police                    90          x\r\n" );
document.write( " \r\n" );
document.write( "Now use DISTANCE = RATE × TIME to fill in the rest of the chart:\r\n" );
document.write( "\r\n" );
document.write( "          DISTANCE       RATE       TIME\r\n" );
document.write( "Robber     80(x+)       80         x+\r\n" );
document.write( "Police       90x          90          x\r\n" );
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document.write( "The robbers and the police both went the same distance, so\r\n" );
document.write( "we set the two distances equal:\r\n" );
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document.write( "80(x+) = 90x\r\n" );
document.write( "80x+40 = 90x\r\n" );
document.write( "  -10x = -40\r\n" );
document.write( "     x = 4\r\n" );
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document.write( "So it took the cops 4 hours to catch the crooks.\r\n" );
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document.write( "The distance was 90x or 90(4) or 360 miles.\r\n" );
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document.write( "Edwin

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