The "equations" below make sense according to a certain pattern. Can you determine what it is?

1. Born leader + middle of the road = BOA
2. The top of the heap + the center of attention = HEN
3. The center of attraction + the end of the line = ACNE
4. The middle of nowhere + the bottom of the barrel = WHEEL

HINT:

Take the clues literally.

Answers:

 1. Born + rOAd = BOA*

2. HEap + atteNtion = HEN

3. attrACtion + liNE = ACNE

4. noWHEre + barrEL = WHEEL

Credit: NY Times Crossword
William Lutwiniak
SPOT ANNOUNCEMENTS  (adapted) 

*B is the leader (leading letter) of BORN / OA is in the middle of ROAD.

Note: See also TAKE THIS LITERALLY