document.write( "Question 44160: solve. approximate irrational roots to the nearest tenth.\r
\n" ); document.write( "\n" ); document.write( "Together Anna and Carla can spray- paint a van in 8 hours. Alone it takes Anna 2 hours less than Carla. Find the time it takes each of them to paint the van alone. Give your answers to the nearest tenth of an hour. (units optional) \n" ); document.write( "
Algebra.Com's Answer #29097 by fractalier(6550)\"\" \"About 
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Let Carla's individual time be c. So Anna's time is c-2.
\n" ); document.write( "We set this one up like this
\n" ); document.write( "t/A + t/B = 1
\n" ); document.write( "8/c + 8/(c-2) = 1
\n" ); document.write( "now multiply by the LCD, c(c-2), and get
\n" ); document.write( "8(c-2) + 8c = c(c-2)
\n" ); document.write( "8c - 16 + 8c = c^2 - 2c
\n" ); document.write( "now collect like terms and solve...
\n" ); document.write( "c^2 - 18c + 16 = 0
\n" ); document.write( "This cannot be factored so let's try completing the square...
\n" ); document.write( "c^2 - 18c + 81 + 16 = 81
\n" ); document.write( "c^2 - 18c + 81 = 65
\n" ); document.write( "(c - 9)^2 = 65
\n" ); document.write( "c - 9 = ± √65
\n" ); document.write( "c = 9 ± √65
\n" ); document.write( "The negative root does not work since that would make Anna's time negative so Carla's time is
\n" ); document.write( "c = 9 + √65 or about 17.1 hours
\n" ); document.write( "Anna can do it in c-2 or about 15.1 hours \n" ); document.write( "
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