document.write( "Question 581274: A teacher must buy 100 treats for exactly $100. Chocolate costs $0.56 each, cupcakes cost $0.92 each, and large cakes cost $2.26 each. How many of each does she buy to have a total of 100 for $100? \n" ); document.write( "
Algebra.Com's Answer #371605 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! A teacher must buy 100 treats for exactly $100. \n" ); document.write( " Chocolate costs $0.56 each, cupcakes cost $0.92 each, and large cakes cost $2.26 each. \n" ); document.write( "How many of each does she buy to have a total of 100 for $100? \n" ); document.write( ": \n" ); document.write( "we got 3 unknowns, and only two equations, calls for some help from our calc \n" ); document.write( ": \n" ); document.write( "Let a = no. of Chocolates \n" ); document.write( "Let b = no. of cupcakes \n" ); document.write( "Let c = no. of large cakes \n" ); document.write( ": \n" ); document.write( "a + b + c = 100 \n" ); document.write( ": \n" ); document.write( ".56a + .92b + 2.26c = 100.00 \n" ); document.write( "multiply by 100 to get rid of the decimals \n" ); document.write( "56a + 92b + 226c = 10000 \n" ); document.write( ": \n" ); document.write( "Multiply the 1st equation by 56, subtract from the above equation \n" ); document.write( "56a + 92b + 226c = 10000 \n" ); document.write( "56a + 56b + 56c = 5600 \n" ); document.write( "----------------------------subtraction eliminates a \n" ); document.write( "0a + 36b + 170c = 4400 \n" ); document.write( "36b = -170c + 4400 \n" ); document.write( "divide by 36, reduce the fractions \n" ); document.write( "b = \n" ); document.write( ": \n" ); document.write( "Only one integer solution for this equation (used the table on a Ti83) \n" ); document.write( "c = 10 cakes \n" ); document.write( "b = 75 cupcakes \n" ); document.write( "then \n" ); document.write( "a = 100 - 85 \n" ); document.write( "a = 15 chocolate \n" ); document.write( ": \n" ); document.write( "See if this checks out by finding total cost \n" ); document.write( ".56(15) = 8.40 \n" ); document.write( ".92(75) = 69.00 \n" ); document.write( "2.26(10)= 22.60 \n" ); document.write( "----------------- \n" ); document.write( "total$ = $100.00 \n" ); document.write( " |