A-1 / a divided by (a squared-a)

A-1 / a divided by (a squared-a)

Original formula = A / (A-1) × 1 / a (A-1)
=1/(a-1)²
=1/(a²-2a+1)

- 1 of a divided by a square + a square - 1 of a

-1/a÷[(a²-1)/(a²+a)]
=-1/a÷【（a+1）（a-1）/a(a+1)]
=-1/a÷（a-1）/a
=1/(1-a)
If you don't understand this question, you can ask,

1. (X-Y + Z) ^ 2 - (X-Y-Z) ^ 2. A-A ^ 5 3. 16 (a-b) + (B-A) ^ 3 4. X ^ 2-y ^ 2 + (x + y) use the square difference formula to decompose the factor
5. 2a(m-n)^3+2a^3(n-m)

1.(x-y+z)^2-(x-y-z)^2 =(2x-2y)(2z)=4z(x-y)
2.a-a^5=a(1-a^4)=a(1+a^2)(1-a^2)=a(1+a^2)(1+a)(1-a)
3.16(a-b)+(b-a)^3=(a-b)[4^2-(a-b)^2]=(a-b)(4+a-b)(4-a+b)
4 .x^2-y^2+(x+y)=(x+y)(x-y)+(x+y)=(x+y)(x-y+1)
5.2a(m-n)^3+2a^3(n-m)=2a(m-n)[(m-n)^2-a^2]
=2a(m-n)(m-n+a)(m-n-a)