Question

How do you factor `25n^2 - 20mn + 4m^2`?

Answer 1

`(5 n -2 m)^2`

Explanation:

`25 n^2 -20 m n +4 m^2`

`= 25 n^2 -10 m n -10 m n+4 m^2`

`=5 n (5 n -2 m) - 2 m( 5 n - 2 m)`

`= (5 n -2 m) (5 n- 2 m)`

`= (5 n -2 m)^2` [Ans]