Question

x la a 2- 4x-45
Ajutor

Answer 1

x^2 - 4x - 45 =

= x^2 - 4x + 4 - 49 =

= (x - 2)^2 - 7^2 =

= (x - 2 + 7)(x - 2 - 7) =

= (x + 5)(x - 9)


m-am folosit de formulele:
(a - b)^2 = a^2 -2ab + b^2
a^2 - b^2 = (a+b)(a-b)

^ = puterea