document.write( "Question 673733: Suppose that Kristin ate two McDonald hamburgers and drank one meduim Coke for a total of 770 calories. Kristins friend Jack ate three hamburgers and drank 2 Cokes for a total of 1260 calories. How many calories are in a McDonalds hamburgers? How many calories are in a meduim coke? \n" ); document.write( "
Algebra.Com's Answer #418834 by Theo(13342)\"\" \"About 
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let x = munber of hamburgers
\n" ); document.write( "let y = number of medium cokes.
\n" ); document.write( "your equations become:
\n" ); document.write( "2x + y = 770
\n" ); document.write( "3x + 2y = 1260
\n" ); document.write( "solve for y in the first equation to get y = 770 - 2x
\n" ); document.write( "substitute for y in the second equation to get:
\n" ); document.write( "3x + 2*(770 - 2x) = 1260
\n" ); document.write( "simplify to get:
\n" ); document.write( "3x + 1540 - 4x = 1260
\n" ); document.write( "combine like terms and subtract 1540 from both sides of the equation go get:
\n" ); document.write( "-4x = 1260 - 1540 which becomes:
\n" ); document.write( "-x = -280
\n" ); document.write( "multiply both sides by -1 to get:
\n" ); document.write( "x = 280
\n" ); document.write( "the number of calories in a mcdonald's hamburger is 280.
\n" ); document.write( "replace x with 280 in either equation and solve for y.
\n" ); document.write( "we'll use the equation of:
\n" ); document.write( "2x + y = 770
\n" ); document.write( "replace x with 280 and you get:
\n" ); document.write( "560 + y = 770
\n" ); document.write( "subtract 560 from both sides to get:
\n" ); document.write( "y = 770 - 560 which becomes:
\n" ); document.write( "y = 210
\n" ); document.write( "the number of calories in a medium code is 210.
\n" ); document.write( "you get:
\n" ); document.write( "x = 280
\n" ); document.write( "y = 210
\n" ); document.write( "x = number of calories in a hamburger.
\n" ); document.write( "y = number of calories in a medium coke.
\n" ); document.write( "2 hamburgers and 1 medium coke is 2 * 280 + 1 * 210 which is equal to 770 calories.
\n" ); document.write( "3 hamburgers and 2 medium cokes is 3 * 280 + 2 * 210 which is equal to 840 + 420 which is equal to 1260 calories.
\n" ); document.write( "numbers check out so the answer is good.\r
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