Answer:
From the given graph,
we get that two points (1,m) and (x,y) is on the line.
To find that the variable m that represents on the graph,
we know that slope of a line passing through two points (x1,y1) and (x2,y2) as,

To find slope of the given line.
Line passes through the points, (0,0) and (1,m)
we get,


Hence m is the slope of the line.
The line passes through the (0,0) and (1,m)
The equation of line is,

we get,



we get,

The equation of the line is,

Hence derived.
The given straight line has slope m and passes through the origin.
y intercept is 0.
It verified the equation of the straight line y=mx.