Respuesta :

Answer:

b/(b+a)

Step-by-step explanation:

(1/a)-(1/b) :[ (b²-a²)/ab²]

first  solve :

common denominator ab

(1/a)-(1/b)  = (b-a)/ab

[b-a/ab] : [(b²-a²)/ab²]

when divide fraction ( division sign turn to (×) and flip the second fraction(reciprocal):

[b-a/ab] × [ab²/ (b²-a²)]

then  simplify : ab²/ab = b

(b-a)×(b/b²-a²)    

factorize : b²-a² = (b-a)(b+a)

(b-a)×(b/(b-a)(b+a))  simplify : (b-a)/b-a = 1

[(b-a)(b)]/[(b-a)(b+a)

b/b+a