document.write( "Question 278160: How do you solve this three variable equation?\r
\n" ); document.write( "\n" ); document.write( "d + e - f = 11
\n" ); document.write( "f + d + 5 = e
\n" ); document.write( "2e - 12 = f \n" ); document.write( "
Algebra.Com's Answer #202507 by ankor@dixie-net.com(22740)\"\" \"About 
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: How do you solve this three variable equation?
\n" ); document.write( "d + e - f = 11
\n" ); document.write( "f + d + 5 = e
\n" ); document.write( "2e - 12 = f
\n" ); document.write( ":
\n" ); document.write( "Arrange all in the same order
\n" ); document.write( "d + e - f = 11
\n" ); document.write( "d - e + f = -5
\n" ); document.write( "0 +2e - f = 12
\n" ); document.write( ":
\n" ); document.write( "Multiply the 1st equation by - 1
\n" ); document.write( "-d - e + f = -11
\n" ); document.write( "d - e + f = -5
\n" ); document.write( "0 + 2e - f = 12
\n" ); document.write( "--------------------adding eliminates d and e, find f
\n" ); document.write( "0 + 0 + f = -4
\n" ); document.write( "f = -4
\n" ); document.write( ":
\n" ); document.write( "Find e using the last equation
\n" ); document.write( "2e - f = 12
\n" ); document.write( "2e - (-4) = 12
\n" ); document.write( "2e + 4 = 12
\n" ); document.write( "2e = 12 - 4
\n" ); document.write( "2e = 8
\n" ); document.write( "e = +4
\n" ); document.write( ":
\n" ); document.write( "Find d using the 1st equation
\n" ); document.write( "d + e - f = 11
\n" ); document.write( "d + 4 (-4) = 11
\n" ); document.write( "d + 4 + 4 = 11
\n" ); document.write( "d = 11 - 8
\n" ); document.write( "d = 3
\n" ); document.write( ":
\n" ); document.write( "Check solutions in the 2nd equation
\n" ); document.write( "d - e + f = -5
\n" ); document.write( "3 - 4 - 4 = -5\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
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