document.write( "Question 173015: My question is how to do substitution. I am extremely confused because with it because my teacher will not explain it well no matter what.
\n" ); document.write( "As an example, questions like these:
\n" ); document.write( "y=5-4*x
\n" ); document.write( "3*x-2*y=12
\n" ); document.write( "Please help and possibly explain in detail how to solve these problems.
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Algebra.Com's Answer #127886 by checkley77(12844)\"\" \"About 
You can put this solution on YOUR website!
Hope these additional comments help.
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\n" ); document.write( "y=5-4x
\n" ); document.write( "Now replace y with(5-4x) in the other equation below & solve for x.
\n" ); document.write( "3x-2y=12
\n" ); document.write( "3x-2(5-4x)=12 multiply 2(5-4x)
\n" ); document.write( "3x-10+8x=12 add (3x8x, add 10 to both sides of the equation)
\n" ); document.write( "11x=12+10 add the (12+10)
\n" ); document.write( "11x=22 (now divide both sides by 11)
\n" ); document.write( "x=22/11 (divide 22 by 11)
\n" ); document.write( "x=2 ans. (now substitute 2 for x in the first equation & solve for y)
\n" ); document.write( "y=5-4*2 (multiply -4*2)
\n" ); document.write( "y=5-8 (subtract 8 from 5)
\n" ); document.write( "y=-3 ans.
\n" ); document.write( "Proof: (replace x with 2 & y with -3 & solve the equation)
\n" ); document.write( "3*2-2*-3=12
\n" ); document.write( "6+6=12\r
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