we are looking for an equation perpendicular to y = -2x + 5
The form: y = mx + b
Where m is the pending; and b is the product of X1 for m, add the Y1
The pending of a line that is perpendicular to other line is reprical to the pending ot this other line, and with a different sign.
So, the pending of this first line is -2, the reprical is -1/2. We change the sing and we have 1/2
The second line does have a pending of 1/2 (0.5).
So, this second line pass for the point (0,0), so we have the equation:
y - Y1 = m(x - X1)
Where Y1 and X1 are the points y and x where pass the line.
If the line pass for the points 0 and 0, so:
y - 0 = m(x - 0)
And the pending we know is 0.5, so
y - 0 = 0.5(x - 0)
We pass to the form slop-intercept:
y = 0.5x - (0.5*0) + 0
The same that:
y = 0.5x
Cause 0+0=0
