Ab and cb form a right angle at the point of intersection b. if the coordinates of a and b are (8, 0) and (2, 1) respectively, then what is the equation of cb ?

Calculating the slope of AB:

m = (0-1)/(2-8) = (1/6)

knowing that CD must be perpendicular, this means it has the negative reciprocal of the slope of AB.

This means that the slope of CD is -6

Using the point-slope formula

(y-1) = -6(x-2)

6x + y =13

sorry, i can't understand your question. will later if you describe more clearly!

: )