Question

find the distance from (2,5) to the line defined by y=2x-4. Express as a radical or a number rounded to the nearest hundredth

Answer 1

one way to do this, is to know that the shortest distance from the point (2,5) to your line is a straight line that is perpendicular to your line.
this second line will have a slope of -1/2 and go through the point (2,5)
find the equation of this line using the point-slope formula
y - y0 = m( x - x0)

then find where this line intersects the first line.
then find the distance between that intersection point and point (2,5)