Answer:
13
Step-by-step explanation:
Recall the binomial theorem.

1. The binomial expansion of
is

Observe that


When we multiply these by
,
•
and
combine to make 
•
and
combine to make 
and the sum of these terms is

2. The binomial expansion is

We get the
term when
:

Answer:
Step-by-step explanation:
6y+9=18
6y=2
y=1/3