'Write down the equation of the line passing through 2,1 and perpendicular to 2x-4y-1=0 I tried figuring out what to do but I don't know how to.
the slope of 2x-4y-1=0 is 1/2
So, the slope if its perpendicular is -2
Now use the point-slope form to write the line through (2,1) with slope -2:
y-1 = -2(x-2)