I have tried solving this again and again but I get wrong answer. (Headbang)

Points A and B have coordinates (2,7) and (-3,-3) respectively. Use a vector method to find the coordinates of C and D, where

(a) C is the point such that AC = 3AB (AC and AB have that arrow for vector notation)

(b) D is the point such that AD = 3/5 AB ..

I only need (a) and I hopefully that will help me understand it.

Thanks