Use exact numbers.
y
=
y=y, equals
x
+
x+x, plus
graph
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
-
2
-
2
-
3
-
3
-
4
-
4
-
5
-
5
-
6
-
6
-
7
-
7
-
8
-
8
-
9
-
9
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
-
2
-
2
-
3
-
3
-
4
-
4
-
5
-
5
-
6
-
6
-
7
-
7
-
8
-
8
-
9
-
9
y
y
x
x