document.write( "Question 158248: X/250The local phone company is offering a phone line plan that costs a fixed monthly charge plus a long distance rate per minute. The plan charges $83.00 for 100 minutes of a long distance calling. For $95.00, you get 500 minutes of long distance calling. Write a linear model for the cost c(in dollars) of the plan for 250 minutes of long distance calling. \n" ); document.write( "
Algebra.Com's Answer #116620 by checkley77(12844)\"\" \"About 
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(100,83) & (500,95)
\n" ); document.write( "RATE LINE=(95-83)/(500-100)
\n" ); document.write( "RL=12/400
\n" ); document.write( "RL=.03
\n" ); document.write( "Y=mX+b
\n" ); document.write( "83=.03*100+b
\n" ); document.write( "83=3+b
\n" ); document.write( "b=83-3
\n" ); document.write( "b=80
\n" ); document.write( "Y=.03X+b
\n" ); document.write( "SETTING Y=250 WE SOLVE FOR X.
\n" ); document.write( "Y=.03*250+80
\n" ); document.write( "Y=7.5+80
\n" ); document.write( "Y=7.5+80
\n" ); document.write( "Y=$87.5 FOR 250 MINUTES.\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
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