(a+b)2/b2-a2 =
= (a^2 + 2ab + b^2)/ b^2 - a^2
= a^2/b^2 + 2ab/b^2 + b^2/b^2 - a^2
= a^2/b^2 + 2a/b + 1 - a^2
= 2a/b + 1
(a+b)2/b2-a2 =
= (a^2 + 2ab + b^2)/ b^2 - a^2
= a^2/b^2 + 2ab/b^2 + b^2/b^2 - a^2
= a^2/b^2 + 2a/b + 1 - a^2
= 2a/b + 1