document.write( "Question 636851: how would I solve and graph these
\n" ); document.write( "x+y=-3, and x+y=7 \n" ); document.write( "

Algebra.Com's Answer #401305 by KMST(5328) $\"\"$ $\"About$

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Those are linear equations.
\n" ); document.write( "The graph of a linear equation is a straight line.
\n" ); document.write( "To draw each line you just need two points.
\n" ); document.write( "To find a point, you just pick a value for the $\"x\"$ or the $\"y\"$ , and solve for the other variable.
\n" ); document.write( "Choose values that make the calculations and the graphing easy.
\n" ); document.write( "Zero is often a good choice.
\n" ); document.write( "Finding points to graph $\"x%2By=-3\"$
\n" ); document.write( "When $\"x=0\"$ , $\"0%2By=-3\"$ --> $\"highlight%28y=-3%29\"$ .
\n" ); document.write( "That gives you point (0,-3).
\n" ); document.write( "When $\"y=0\"$ , $\"x%2B0=-3\"$ --> $\"highlight%28x=-3%29\"$ .
\n" ); document.write( "That gives you point (-3,0).
\n" ); document.write( "Finding points to graph $\"x%2By=7\"$
\n" ); document.write( "When $\"x=0\"$ , $\"0%2By=7\"$ --> $\"highlight%28y=7%29\"$ .
\n" ); document.write( "That gives you point (0,7).
\n" ); document.write( "When $\"y=0\"$ , $\"x%2B0=7\"$ --> $\"highlight%28x=7%29\"$ .
\n" ); document.write( "That gives you point (7,0).
\n" ); document.write( "The graph (with the points circled, looks like this:
\n" ); document.write( "

The line for $\"x%2By=-3\"$ is drawn in blue.
\n" ); document.write( "The lines are parallel.
\n" ); document.write( "As a system of linear equations,
\n" ); document.write( " $\"system+%28x%2By=-3%2Cx%2By=7%29\"$ has no solution.
\n" ); document.write( "That should be obvious from the start, because if $\"x%2By\"$ is $\"-3\"$ ,
\n" ); document.write( "it cannot be $\"7\"$ at the same time (for the same $\"x\"$ and $\"y\"$ ). \n" ); document.write( "

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