document.write( "Question 55067: Solve the system by graphing, addition and substitution methods. x + y = 3, x + y = –1 \n" ); document.write( "
Algebra.Com's Answer #37300 by funmath(2933)\"\" \"About 
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Solve the system by graphing, addition and substitution methods.
\n" ); document.write( "x + y = 3, x + y = –1
\n" ); document.write( "These lines are parallel and do not intersect, therefore this system has no solution.
\n" ); document.write( ":
\n" ); document.write( "Graphically:
\n" ); document.write( "\"graph%28300%2C200%2C-10%2C10%2C-10%2C10%2C-x%2B3%2C-x-1%29\"
\n" ); document.write( ":
\n" ); document.write( "Addition:
\n" ); document.write( "x+y=3
\n" ); document.write( "x+y=-1
\n" ); document.write( "------Multiply either equation by -1 and add them together.
\n" ); document.write( "x+y=3
\n" ); document.write( "-1(x+y)=-1(-1)
\n" ); document.write( "---
\n" ); document.write( "x+y=3
\n" ); document.write( "-x-y=1
\n" ); document.write( "_________
\n" ); document.write( "0x+0y=4
\n" ); document.write( "0=4
\n" ); document.write( "0 does not equal 4 and we can't solve for a variable, there's no solution.
\n" ); document.write( ":
\n" ); document.write( "Substitution:
\n" ); document.write( "x+y=3
\n" ); document.write( "x+y=-1
\n" ); document.write( "--------solve the first equation for y and substitute that in for y in the second equation and solve for x.
\n" ); document.write( "-x+x+y=3-x
\n" ); document.write( "y=3-x
\n" ); document.write( "--
\n" ); document.write( "x+(3-x)=-1
\n" ); document.write( "x+3-x=-1
\n" ); document.write( "3=-1
\n" ); document.write( "3 does not equal -1 and we can't solve for x, there's no solution.
\n" ); document.write( "Happy Calculating!!! \n" ); document.write( "
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