25

196r - p = (14r)  - p  = (14r - p)(14r + p)
25x - 289y = (5x) -  (17y) = (5x - 17y)(5x+17y)
ab - 9c  = (ab)  - (3c)  = (ab - 3c)(ab  + 3c)
(m - 1) - 121  =  (m - 1)  - 11  = (m-1 - 11)(m-1 +11) = (m - 12)(m + 10)
c - 2cm +  m  = (c  - m)  = (c-m)(c-m)
9 + 6c  + c  = c  + 2*3*c + 3  = (c + 3)  = (c+3)(c+3)
81c -36cm +4m = (9c)  - 2*9c*2m  + (2m) = (9c - 2m) = (9c-2m)(9c-2m)
125 + n = n + (5)  = (n+5)(n + 5n + 5) = (n + 5)(n + 5n + 25)


25c + 10cm + m = (5c) + 2*5c*m  + m = 5c(5c + 2m) + m  = ???
если только не пропущена ступень m:
25с  + 10сm  + m  = (5c)  + 2*5c*m  + (m) =(5c+m) = (5c+m)(5c+m)