Question 68590
solve each of the following systems by graphing...
2x -y = 4, 2x -y = 6 
Notice that the coefficients of x and y are exactly the same, but the constant is different?  That means that the two lines are parallel and will never intersect, therefore this system has no solution.
However, for giggles, let's graph the two lines anyway...
For 2x-y=4
Let x=0 and solve for y,
{{{2(0)-y=4}}}
{{{0-y=4}}}
{{{-y/-1=4/-1}}}
{{{y=-4}}} Plot (0,-4)
Now let y=0 and solve for x,
{{{2x-0=4}}}
{{{2x/2=4/2}}}
{{{x=2}}} Plot (2,0)
Connect the points and you have a line:
{{{graph(300,200,-10,10,-10,10,2x-4)}}}
For 2x-y=6
Let x=0 and solve for y
{{{2(0)-y=6}}}
{{{0-y=6}}}
{{{-y/-1=6/-1}}}
{{{y=-6}}}  Plot (0,-6)
Now let y=0 and solve for x
{{{2x-0=6}}}
{{{2x/2=6/2}}}
{{{x=3}}} Plot (3,0)
Connect the two points and you have another line:
{{{graph(300,200,-10,10,-10,10,2x-4,2x-6)}}}
The lines are parallel, never intersect, and never have a solution.
Happy Calculating!!!!