document.write( "Question 107873: Suppose you have a lemonade stand, and when you charge $2 per cup of lemonade you sell 120 cups. But when you raise your price to $3 you only sell 60 cups. Write an equation for the number of cups you sell as a function of the price you charge. Denote \"C\" for number of cups, and \"P\" for the price you charge. Assume the function is linear.
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document.write( "This is what I have so far, please help!
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document.write( "Linear function: C(P)=Pm+b
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document.write( "Price- $2, cups sold- 120
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document.write( "Price- $3, cups sold- 60
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document.write( "Take 120 from 60 we get a= -60
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Algebra.Com's Answer #78635 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! Let x=price, y=# of cups sold\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So when x=2, then y=120 (ie you sell 120 cups at $2). So that means you have the point (2,120). Now let ( \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Also when x=3, then y=60 (ie you sell 60 cups at $3). So that means you have the point (3,60). Now let ( \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So we have two points (2,120) and (3,60)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now let's find the equation of the line through those points\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "First lets find the slope through the points ( \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the slope is\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------Point-Slope Formula------ \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So lets use the Point-Slope Formula to find the equation of the line\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------------------------------------------------------------------------------------------------------------\r \n" ); document.write( "\n" ); document.write( "Answer:\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the equation of the line which goes through the points ( \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The equation is now in \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Notice if we graph the equation \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Notice how the two points lie on the line. This graphically verifies our answer.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since the equation is |