Find the sum
a
-
b
a
+
b
+
3
a
-
2
b
a
+
b
+
5
a
-
3
b
a
+
b
+
.
.
.
t
o
12
t
e
r
m
s
Matching exercise
Match the items on the right to the items on the left.
Check
OK
Step 1
Step 2
Step 3
Step 4
Step 6
Step 7
Step 8
Step 9
