Factorize :
x
2
+
4
x
-
21
Matching exercise
Match the items on the right to the items on the left.
Check
OK
Step 1
Step 2
Step 3
Step 4
x
2
+
4
x
-
21
=
x
2
+
7
x
-
3
x
-
21
=
x
2
+
7
x
-
3
x
+
21
=
x
(
x
+
7
)
-
3
(
x
+
7
)
=
(
x
+
7
)
(
x
-
3
)