document.write( "Question 1013977: Using substitution method:4x-5y=39,-2x+7y=-51 \n" ); document.write( "
Algebra.Com's Answer #630323 by ankor@dixie-net.com(22740)\"\" \"About 
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Using substitution method:
\n" ); document.write( " 4x-5y=39,
\n" ); document.write( "-2x+7y=-51
\n" ); document.write( ":
\n" ); document.write( "Use the 2nd equation for substitution
\n" ); document.write( "-2x = -7y - 51
\n" ); document.write( "divide both sides by -2
\n" ); document.write( "x = 3.5y + 25.5
\n" ); document.write( ":
\n" ); document.write( "Substitute (3.5y+25.5) for x in the 1st equation
\n" ); document.write( "4(3.5y+25.5) - 5y = 39
\n" ); document.write( "14y + 102 - 5y = 39
\n" ); document.write( "14y - 5y = 39 - 102
\n" ); document.write( "9y = -63
\n" ); document.write( "y = -63/9
\n" ); document.write( "y = -7
\n" ); document.write( ":
\n" ); document.write( "Find x, replace y with -7
\n" ); document.write( "x = 3.5(-7) + 25.5
\n" ); document.write( "x = -24.5 + 25.5
\n" ); document.write( "x = 1
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check solutions in the 1st equation: 4x-5y=39,
\n" ); document.write( "4(1) - 5(-7) = 39
\n" ); document.write( "4 + 35 = 39
\n" ); document.write( " \n" ); document.write( "
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