Answer:
5 + 40 d
Step-by-step explanation:
Hey there,
To simply this you have to multiply each term in the brackets by 5.
<u>Further explanation</u>
5 ( 1 + 8 d )
5 × 1 + 5 × 8 d
5 +40 d
Hope this helps you.
Let me know if you have any other question :-)