document.write( "Question 830042: How can I solve each system of equations? Example, x+y=-3 x-y=1 I think it has to do with substitution. \n" ); document.write( "
Algebra.Com's Answer #500304 by LinnW(1048)\"\" \"About 
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To use substitution we need to solve for x in one of the equations.
\n" ); document.write( "Let's take x-y=1
\n" ); document.write( "subtract y from each side
\n" ); document.write( "x = y + 1
\n" ); document.write( "The other equation is
\n" ); document.write( "x + y = -3
\n" ); document.write( "Substitute (y + 1) for x in this equation.
\n" ); document.write( "(y + 1) + y = -3
\n" ); document.write( "2y + 1 = -3
\n" ); document.write( "add -1 to each side
\n" ); document.write( "2y = -4
\n" ); document.write( "divide each side by 2
\n" ); document.write( " y = -2
\n" ); document.write( "Now substitute -2 for y in x = y + 1
\n" ); document.write( "x = -2 + 1
\n" ); document.write( "x = -1
\n" ); document.write( " \n" ); document.write( "
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