Помогите сократить дробь:

1) 12 х^9 y^5/18x y6 =

2) 5a - 15/10a =

3) m^2 - n^2/m+n =

4) m^2-1/1+m =

5) m^2-1/m^2-2m+1 =

6) x^2-8x+16/x^2-16 =

1) 12 х^9 y^5/18x y6 = 2x⁸ * 3y

2) 5a - 15/10a = 5 (a-3) / 10a = a-3 / 2a

3) m^2 - n^2/m+n = (m-n) (m+n) / (m+n) = m-n

4) m^2-1/1+m = (m-1) (m+1) / 1+m = m-1

5) m^2-1/m^2-2m+1 = (m-1) (m+1) / (m-1) ² = m+1 / m-1

6) x^2-8x+16/x^2-16 = (x-4) ² / (x-4) (x+4) = x-4 / x+4