Respuesta :

Answer:

Step-by-step explanation:

Numerator = y/ab - ab

   = y/ab - ab * ab/ab       (LCM = ab)

 =  (y - a²b²)/ab

Denominator = 1/a - a/b

                      = 1*b/a*b - a*a/b*a   (LCM = ab)

                      = (b-a²)/ab

(y/ab - ab ) / ( 1/a - 1/b) = (y - a²b²)/ab  *  ab/ (b-a²)

= (y - a²b²)/ (b-a²)