I have to guess the missing text.
y=f(x)=2a/(x+2)² passes through the point x=-1, y=-1.
Therefore -1=2a/(-1+2)²=2a, a=-½ and f(x)=-1/(x+2)².
Another guess: y=f(x)=2ax/(x+2)².
Plug in (-1,-1):
-1=-2a, a=½, f(x)=1/(x+2)².
Another guess: y=f(x)=ax²/(x+2)².
Plug in (-1,-1):
-1=a, y=-x²/(x+2)².