document.write( "Question 1027656: an electric utility company charges residential customers 11,5 cents per kilo-watt hour plus a base charge each month.1 customer's monthly bill comes to $51,65 for 380 kilowatt hours.Find a linear function that describes the total monthly charges for electricity if x is the number of kilowatt hours used in a month ? \n" ); document.write( "

Algebra.Com's Answer #642901 by josmiceli(19441) $\"\"$ $\"About$

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Plot monthly charges, $\"+C+\"$ , in cents, on the vertical axis
\n" ); document.write( "Plot number of kilowatt hours used per month, $\"+x+\"$
\n" ); document.write( "on the horizontal axis
\n" ); document.write( "----------------------
\n" ); document.write( " $\"+11.5+\"$ cents / kWh is the slope of the line
\n" ); document.write( "----------------------
\n" ); document.write( "( 380, 5165 ) is given as a point on the line
\n" ); document.write( "( note that I converted the cost to cents )
\n" ); document.write( "----------------------
\n" ); document.write( "Use the general point-slope formula
\n" ); document.write( " $\"+%28+C+-+5165+%29+%2F+%28+x+-+380+%29+=+11.5+\"$
\n" ); document.write( " $\"+C+-+5165+=+11.5%2A%28+x+-+380+%29+\"$
\n" ); document.write( " $\"+C+=+11.5x+%2B+5165+-+11.5%2A380+\"$
\n" ); document.write( " $\"+C+=+11.5x+%2B+5165+-+4370+\"$
\n" ); document.write( " $\"+C+=+11.5x+%2B+795+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "check the answer:
\n" ); document.write( "( 380, 5165 )
\n" ); document.write( " $\"+C+=+11.5x+%2B+795+\"$
\n" ); document.write( " $\"+5165+=+11.5%2A380+%2B+795+\"$
\n" ); document.write( " $\"+5165+=+4370+%2B+795+\"$
\n" ); document.write( " $\"+5165+=+5165+\"$
\n" ); document.write( "OK
\n" ); document.write( "( note that if no electricity is used, you still pay $7.95/month )\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " \n" ); document.write( "

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