9514 1404 393
Answer:
33 ft
Explanation:
The perimeter formula for a rectangle is ...
P = 2(L +W)
Filling in the given numbers, we have ...
146 = 2(40 +W)
73 = 40 +W . . . . . . . divide by 2
33 = W . . . . . . . . . . . subtract 40
The backyard is 33 feet wide.