diff --git a/education/software development/ECE1400/Chapter 4 Exercises.md b/education/software development/ECE1400/Chapter 4 Exercises.md
index bc7819a..d76aac6 100644
--- a/education/software development/ECE1400/Chapter 4 Exercises.md	
+++ b/education/software development/ECE1400/Chapter 4 Exercises.md	
@@ -8,9 +8,8 @@ a. `1`
 b. `-1`, `-2`
 c. `-1`, `-1`
 d. `1`, `2`
-
 # 9.
-
+a. 
 
 # 11.
 # 15.