document.write( "Question 90658: solve the system by addition or substitution 20x - 5y = -12
\n" ); document.write( " y = 4x +3
\n" ); document.write( "Thank you. \n" ); document.write( "

Algebra.Com's Answer #65789 by stanbon(75887) $\"\"$ $\"About$

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solve the system by addition or substitution 20x - 5y = -12
\n" ); document.write( " y = 4x +3
\n" ); document.write( "--------------------------
\n" ); document.write( "Substitute y=4x+3 into the 1st equation to get:
\n" ); document.write( "20x - 5(4x+3) = -12
\n" ); document.write( "20x -20x -15 = -12
\n" ); document.write( "-15 = -12
\n" ); document.write( "This is a contradiction.
\n" ); document.write( "There is no solution for the system of equations.
\n" ); document.write( "------------
\n" ); document.write( "If you graph the two equations you will notice the lines are parallel:
\n" ); document.write( "Solving the 1st equation for y you get:
\n" ); document.write( "y = 4x+(12/5)
\n" ); document.write( "Graphing both equations you get:
\n" ); document.write( " $\"graph%28400%2C300%2C-10%2C10%2C-10%2C10%2C4x%2B%2812%2F5%29%2C4x%2B3%29\"$
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( " \n" ); document.write( "

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