Answer:

Explanation:
Given

Friend = $35 more expensive than yours.
Brother = 3 * as much as your friend
Required
Write an expression for the cost of your brother's drone
I'll solve by analysing the question one sentence after the other
You:

Your friend:
Friend = $35 more expensive than yours.
This means

Substitute d for You

Your brother:
Brother = 3 * as much as your friend
This means:

Substitute 35 + d for Friend

Open bracket

