document.write( "Question 471335: Patricia Burgess knows that at some point during the calender year her basic monthly telephone rate increased from $17.10 to $18.40. If she paid a total of $207.80 for basic telephone service for the calender year, in what month did the rate increase take effect \n" ); document.write( "
Algebra.Com's Answer #323256 by ankor@dixie-net.com(22740)\"\" \"About 
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during the calender year her basic monthly telephone rate increased from $17.10 to $18.40.
\n" ); document.write( "If she paid a total of $207.80 for basic telephone service for the calender year, in what month did the rate increase take effect
\n" ); document.write( ":
\n" ); document.write( "Let m = no. months she paid $17.10
\n" ); document.write( "then
\n" ); document.write( "(12-m) = no. of months she paid $18.40
\n" ); document.write( ":
\n" ); document.write( "17.10m + 18.40(12-m) = 207.80
\n" ); document.write( "17.10m + 220.80 - 18.40m = 207.80
\n" ); document.write( "17.10m - 18.40m = 207.80 - 220.80
\n" ); document.write( "-1.30m = -13
\n" ); document.write( "m = \"%28-13%29%2F%28-1.3%29\"
\n" ); document.write( "m = +10 months at the lower rate, then the increase took effect in the 11th month (Nov)
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "see if that's true
\n" ); document.write( "10(17.10) + 2(18.40) =
\n" ); document.write( "171.00 + 36.80 = 207.80
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