ХЕЛП
(2x - 1) (2x + 1)
(m - 5k) (5k + m)
(1 + 3p) (3p -1)
(4y + m) (m - 4y)

4х2-1 формула-(25к2+м2)

(2х-1)(2х+1)=4х^2+2х-2х-1=4х^2-1 ... (m-5k)(5k+m)=5km+m^2-25k^2-5km=m^2-25k^2 ... (1+3p)(3p-1)=3p-1+9p^2-3p=9p^2-1 .............. (4y+m)(m-4y)=4ym-16y^2+m^2-4ym=m^2-16y^2