Which expression is equivalent to
(
6
x
3

5
x
2

6
)
+
(
3
x
2
+
10

9
x
3
)
?


9
x
3

4
x
2
+
4

9
x
3

4
x
2
+
4


3
x
3

2
x
2
+
4


3
x
3

2
x
2
+
4


3
x
3
+
8
x
2

4


3
x
3
+
8
x
2

4

14
x
3
+
8
x
2
+
16