Respuesta :
A=πr²
pool=π(y-4)²=π(y²-8y+16)
total=π(y+4)²=π(y²+8y+16)
walkway=total-pool
walkway=π(y²+8y+16)-π(y²-8y+16)=
π(y²+8y+16-y²+8y-16)=
Ï€(16y)=
16Ï€y
first option is answer
pool=π(y-4)²=π(y²-8y+16)
total=π(y+4)²=π(y²+8y+16)
walkway=total-pool
walkway=π(y²+8y+16)-π(y²-8y+16)=
π(y²+8y+16-y²+8y-16)=
Ï€(16y)=
16Ï€y
first option is answer