To simplify the expression 8a(a+b)+a(a+b), we can first distribute the 'a' inside the parentheses:

= 8a^2 + 8ab + a^2 + ab
= 9a^2 + 9ab

Therefore, 8a(a+b)+a(a+b) simplifies to 9a^2 + 9ab.

Now, let's simplify the expression km + kn + 9m + 9n:

Combining like terms, we get:
= (k + 9)m + (k + 9)n
= (k + 9)(m + n)
= k(m + n) + 9(m + n)
= km + kn + 9m + 9n

Therefore, km + kn + 9m + 9n simplifies to (k + 9)(m + n).