Please answer this question (Link above). It is worth 50 points and I will mark brainliest

Which is an equation for the nth terms of the sequence 12,15,18,21

Haley buys 9 pounds of apples for $3. how many pounds of apples can she buy for $1?

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?