You have the following expression:
6n + 5(9 + 8n)
in order to simplify the previous expression, proceed as follow:
6n + 5(9 + 8n) apply distribution property
= 6n + 45 + 40n order like terms
= 6n + 40n + 45 simplify like terms
= 46n + 45
Hence, the simplified expression is 46n + 45
