document.write( "Question 976182: Solve the following system of equations using the substitution method
\n" ); document.write( "5x-7y= -18
\n" ); document.write( "4x+ 3y = 20 \n" ); document.write( "
Algebra.Com's Answer #598797 by Cromlix(4381)\"\" \"About 
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5x-7y= -18....(1)
\n" ); document.write( "4x+ 3y = 20...(2)\r
\n" ); document.write( "\n" ); document.write( "Altering (2)
\n" ); document.write( "4x + 3y = 20
\n" ); document.write( "4x = 20 - 3y
\n" ); document.write( "x = 5 - 3/4y
\n" ); document.write( "...........
\n" ); document.write( "Substituting in:-
\n" ); document.write( "5x - 7y = -18
\n" ); document.write( "5(5 - 3/4y) - 7y = -18
\n" ); document.write( "25 - 15/4y - 7y = -18
\n" ); document.write( "Convert 7 into 28/4
\n" ); document.write( "25 - 15/4y - 28/4y = - 18
\n" ); document.write( "25 - 43/4y = - 18
\n" ); document.write( "- 43/4y = -18 - 25
\n" ); document.write( "- 43/4y = - 43
\n" ); document.write( "43/4y = 43 (Multiply both sides by -1)
\n" ); document.write( "43y = 43 x 4
\n" ); document.write( "43y = 172
\n" ); document.write( " y = 172/43
\n" ); document.write( "y = 4
\n" ); document.write( "Substitute y = 4 into
\n" ); document.write( "4x + 3y = 20
\n" ); document.write( "4x + 3(4) = 20
\n" ); document.write( "4x + 12 = 20
\n" ); document.write( "4x = 20 - 12
\n" ); document.write( "4x = 8
\n" ); document.write( "x = 2
\n" ); document.write( "{2,4}
\n" ); document.write( "Hope this helps:-)\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
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