Răspuns:
Vom descompune in factori expresiile
4a^2 - y^2 - 2a - y =
(4a^2 - y^2) - (2a + y) =
(2a - y)(2a + y) - (2a + y) =
(2a + y)(2a - y - 1)
9x^2 + 3x - 6xy + y^2 - y =
9x^2 - 6xy + y^2 + 3x - y =
(3x - y)(3x - y) + (3x - y) =
(3x - y)(3x - y - 1)
5b - 4y - 16y^2 + 25b^2 =
5b - 4y + 25b^2 - 16y^2 =
5b - 4y + (5b - 4y)(5b + 4y) =
(5b - 4y) (1 + 5b + 4y)
