Answer:
(8m+24n) is our final answer.
Explanation:
Given:
(m+3n)8 ...
We have to simplify this.
Applying distributive property of multiplication:
Distributive property:
When a number is multiplied by a sum of two numbers then we will multiply 'the number' first with the number inside the parentheses then add it and again multiply 'the number' with the next number.

So,
⇒

⇒

⇒

Our final answer is (8m+24n).