Question 789094
Note: I can tell that the system {{{system(4x+2y=-8,2x+y=-4)}} has infinite solutions. The lines are the same. The equation {{{2x+y=-4}}}, can be transformed into the equivalent equation {{{4x+2y=-8}}}by multiplying both sides of the equal sign times 2. If a point is a solution of one equation, it is a solution of the other one. All the points in the line are intersection points and solutions.
 
To graph one line you need to plot two points and connect them with a straight line.
Using grid paper is recommended.
For {{{2x+y=-4}}}
Substituting {{{x=0}}}gives us {{{y=-4}}} and we have the point (0,-4).
Substituting {{{y=0}}}gives us {{{2x=-4}}}-->{{{x=-2}}} and we have the point (-2,0).
For {{{4x+2y=-8}}},
we could substitute {{{x=0}}} and {{{y=0}}} to get
{{{x=0}}}-->{{{2y=-8}}}-->{{{y=-4}}} for point (0,-4), and
{{{y=0}}}-->{{{4x=-8}}}-->{{{x=-8/4}}}-->{{{x=-2}}} for point (-2,0)
{{{drawing(300,300,-5,5,-5,5,
grid(1),line(-5,6,1,-6),
blue(circle(0,-4,0.1)),blue(circle(-2,0,0.1)),
green(circle(0,-4,0.2)),green(circle(-2,0,0.2))
)}}} The points are the same for both lines because both lines are the same.