∣z−(3−2i)∣≤4 represents a circle whose centre is (3,−2) and radius =4. ∣z∣=∣z−0∣ represents the distance of point ' z ' from origin (0,0) 
Suppose RS is the normal of the circle passing through origin ' O ' and G is its center (3,−2) Here, OR is the least distance and OS is the greatest distance OR=RG−OG and OS=OG+GS…(1) As, RG=GS=4 OG=32+(−2)2=9+4=13 From (1), OR=4−13 and OS=4+13 So, required difference =(4+13)−(4−13)=13+13=213