Determine the value of r such that the line through (5, r) and (2, 3) is perpendicular to the line y = 2x ­- 4 r = 1.5 r = 9 r = ­- 3 r = 4.5

So, what's the slope of y = 2x - 4?  well, is in slope-intercept form, thus

, so is 2.

now, a perpendicular line to that, will have a negative reciprocal slope to it, thus



so, that's its slope of that perpendicular line.

but we also know that it runs through (5,r) and (2,3), so that slope is equal to -1/2

The answer is a hope i