Respuesta :

 the least common denominator is (y-7) (y+7) (y-1)

y/y^2-49 and y/y^2+6y-7

We can factor the first denominator into

y^2-49 = (y-7) (y+7) by using the difference of squares

                                                      (a^2-b^2) = (a-b)(a+b)

We can factor the second denominator into

y^2+6y-7 = (y+7)(y-1) by factoring.

What two terms multiply to -7 and add to -6    

7*-1 = -7

7-1 =6

(y+7)(y-1)

We need to take the greatest number from either each term                                                      

The first term has (y-7) (y+7)

The second term has (y+7)(y-1)

We have one (y-7) in each term

We have one (y+7) in each term

We have one (y-1) in each term

(y-7) (y+7) (y-1)