Let us furst square both sides. This will give us a^2(n+1)=b^2(n-1). From here, we can subtract a^2 from both sides: na^2+a^2=nb^2-b^2 turns into na^2=nb^2-b^2-a^2.
Now, we can subtract nb^2 from both sides and get na^2-nb^2=-b^2-a^2.Now, factor out the n and divide both sides by a^2-b^2. Therefore, n in terms of b and a is: \(\frac{-b^2-a^2}{a^2-b^2}\)