Aperpendicular bisector, cd is drawn through point c on ab. if the coordinates of point a are (-3, 2) and the coordinates of point b are (7, 6), the x-intercept of cd is[ a(3,0) b(18/5,0) c(9,0) d(45/2,0) ] . point [ a(-52,117) b(-20,57) c(32,-71) d(-54,-128) ] lies on cd

The slope of AB is (6 - 2) / (7 + 3) = 2/5. Therefore, the slope of the perpendicular bisector is -5/2. The midpoint of AB is [(-3 + 7)/2, (2 + 6)/2] = (2, 4). Therefore the equation of CD is:
y = (-5/2)x + b, and substituting (2, 4):
4 = -5 + b
b = 9
y = (-5/2)x + 9

The x-intercept is 0 = (-5/2)x + 9
x = 18/5, so the x-intercept is (18/5, 0), which is choice B.

Substituting the four given points reveals that only the 3rd choice: C(32, -71) fits the equation of the line, as:
-71 = (-5/2)(32) + 9
-71 = -80 + 9
-71 = -71 is true, while all the other 3 points don't fit.

21, i'm pretty sure it's right lol