Perpendicular means opposite and reciprocal (in reference to the slope).
The opposite of 1/2 is -1/2. The reciprocal of -1/2 is -2.
Now we know the slope we can plug the point they gave us into the X and Y positions to solve for b (in the point (2, 3) there is a X - Value (2) and a Y-value (3)
y= -2x+b
3= -2(2)+b
3= -4+b
1=b
Now we plug b and the slope in the generic y=mx+b equation:
y= -2x+1
