We can find the solution of a system of linear equations br graphing the lines, the point where the lines intersect is the solution of the system.
To graph a line we only need to find two points of it and the join them.
-first equation y = -2x -4
Let's take for example x equals 0, then we get:
y= -2*0 -4 = -4
Then we have the point (0,-4)
Let's take x equals -2:
y= -2*(-2) -4 = 4 -4 = 0
Then, we have the point (-2,0)
-second equation
If we take x equals 0, then we have:
y= 0-1 = -1
Then we have the point (0,-1)
If we take x equals -2, then we have:
y= -2 -1 = -3
Then, we have the point (-2,-3)
Now that we know two points of each line, let's plot them:
As you can see in the graph, the lines intersect at the point (-1,-2) then, that is the solution of the system of equation