Question 174900
{{{graph(300,300,-10,10,-10,10,-2*x,-1/2*x)}}}

Using the graph, the point of intersection appears to be {0,0}.

Check to see if {0,0} satisfies the system of equations

y+2*x=0
x+2*y=0

Replace x and y with x=0 and y=0 in the two equations.

0+2*0 = 0

0+2*0 = 0

So the point {0,0} satifies the system of equations and it is a solution.

I hope that this helps.