diff --git a/ex1.2.scm b/ex1.2.scm
new file mode 100644
index 0000000..063462f
--- /dev/null
+++ b/ex1.2.scm
@@ -0,0 +1,2 @@
+(/ (+ 5 4 (- 2 (- 3 (+ 6 (/ 4 5)))))
+   (* 3 (- 6 2) (- 2 7)))
\ No newline at end of file
diff --git a/ex1.3.scm b/ex1.3.scm
new file mode 100644
index 0000000..d6afd40
--- /dev/null
+++ b/ex1.3.scm
@@ -0,0 +1,24 @@
+(define (square x) 
+  (* x x))
+
+(define (sum-of-squares a b) 
+  (+ (square a) (square b)))
+
+(define (square-of-two-larger a b c)
+  (cond ((and (>= a b) (>= b c)) (sum-of-squares a b))
+	((and (>= a c) (>= c b)) (sum-of-squares a c))
+	((and (>= b a) (>= a c)) (sum-of-squares b a))
+	((and (>= b c) (>= c a)) (sum-of-squares b c))
+	((and (>= c a) (>= a b)) (sum-of-squares c a))
+	((and (>= c b) (>= b a)) (sum-of-squares c b))))
+
+(square-of-two-larger 2 3 4)
+(square-of-two-larger 2 4 3)
+(square-of-two-larger 3 2 4)
+(square-of-two-larger 3 4 2)
+(square-of-two-larger 4 2 3)
+(square-of-two-larger 4 3 2)
+(square-of-two-larger 3 3 3)
+(square-of-two-larger 2 3 3)
+(square-of-two-larger 3 2 3)
+(square-of-two-larger 3 3 2)
\ No newline at end of file
diff --git a/ex1.5.scm b/ex1.5.scm
new file mode 100644
index 0000000..1eada56
--- /dev/null
+++ b/ex1.5.scm
@@ -0,0 +1,8 @@
+(define (p) (p))
+
+(define (test x y)
+  (if (= x 0)
+      0
+      y))
+
+(test 0 (p))