document.write( "Question 484136: have one question left on a summer packet, not sure how to answer. need to sketch both equations on the same x-y plane..company A offers a cell phone fee of $90/mnth...company B costs $15per month for service and $.10 per minute...need to compare the 2 plans ??????????????????? \n" ); document.write( "
Algebra.Com's Answer #331254 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
sketch both equations on the same x-y plane.
\n" ); document.write( ".company A offers a cell phone fee of $90/mnth.
\n" ); document.write( "..company B costs $15per month for service and $.10 per minute.
\n" ); document.write( ".need to compare the 2 plans:
\n" ); document.write( ":
\n" ); document.write( "Plan A offers a flat $90 with unlimted calling, the equation for that
\n" ); document.write( "y = 90
\n" ); document.write( ":
\n" ); document.write( "Let t = no. of min used in Plan B
\n" ); document.write( "y = .10m + 15
\n" ); document.write( ":
\n" ); document.write( "Plot these two equation, should look like this,
\n" ); document.write( "x axis, no of minutes
\n" ); document.write( "y axis total cost per month
\n" ); document.write( "\"+graph%28+300%2C+200%2C+-500%2C+1000%2C+-40%2C+110%2C+90%2C+.10x%2B15%29+\"
\n" ); document.write( "You can see that Plan A is just a horizontal line at y=90 (Red)
\n" ); document.write( "Plan B cost increases with the number of minutes used
\n" ); document.write( "To find how many minutes for them to cost the same write
\n" ); document.write( ".10m + 15 = 90
\n" ); document.write( ".10m = 90-15
\n" ); document.write( ".10m = 75
\n" ); document.write( "m = \"75%2F.1\"
\n" ); document.write( "m = 750 mins which is illustrated by the graph
\n" ); document.write( ":
\n" ); document.write( "To summarize, if you use more than 750 min Plan A is best if you use less Plan B is best, right? \n" ); document.write( "
\n" );