document.write( "Question 1005787: Please help me solve this weighted average problem ;
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document.write( "Your friends math test contained 42 questions some of which were worth 2 points , while the rest were worth 3 points.Your friend tells you that a perfect score is 100 points, but she cannot remember how many of each type were on the test . Help your friend out , how many of each type were on the test? \n" );
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Algebra.Com's Answer #621947 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "x = number of 2 point questions \n" ); document.write( "y = number of 3 point questions\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are 42 questions total, so, \n" ); document.write( "x+y = 42\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for y to get \n" ); document.write( "y = 42-x \n" ); document.write( "y = -x+42\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are x questions that are 2 points each. In total, we have 2x points just for these types of questions.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are y questions that are 3 points each. In total, we have 3y points just for these types of questions.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The grand total is 2x+3y points. We're given the grand total to be 100.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the second equation is 2x+3y = 100\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now we will replace the y in the second equation with -x+42 then solve for x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2x+3y = 100 \n" ); document.write( "2x+3(-x+42) = 100 \n" ); document.write( "2x-3x+126 = 100 \n" ); document.write( "-x+126 = 100 \n" ); document.write( "-x+126-126 = 100-126 \n" ); document.write( "-x = -26 \n" ); document.write( "x = 26\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use this x value to find the value of y\r \n" ); document.write( "\n" ); document.write( "y = -x+42 \n" ); document.write( "y = -26+42 \n" ); document.write( "y = 16\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Summary: \n" ); document.write( "x = 26 and y = 16\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are 26 two point questions and 16 three point questions. \n" ); document.write( " |