Question 319057
Solve the system of equations:
{{{system(x+2y=8,
x=9-2y)}}}
<pre><b>
Substitute {{{(9-2y)}}} for x in

{{{x+2y=8}}}

{{{(9-2y)+2y=8}}}

{{{9-2y+2y=8}}}

{{{9-cross(2y)+cross(2y)=8}}}

{{{9=8}}}

That's a false numerical equation, so the
system is inconsistent.  So if you graph both
equations by plotting points, you get these two 
parallel lines below, which will never intersect 
and so there is no common solution to both 
equations:

{{{drawing(400,400,-5,5,-2,8,

graph(400,400,-5,5,-2,8,(8-x)/2),

graph(400,400,-5,5,-2,8,(x-9)/(-2)) )}}}

Edwin</pre>