Pe baza formulei de calcul sunt toate
(a+b)(a-b) = a^2 - b^2
a) x^2 - 49 = (x-7)(x+7)
b) x^2 - 64 = (x-8)(x+8)
c) x^2 - 100 = (x-10)(x+10)
d) x^2 - 121 = (x-11)(x+11)
e) 4x^2 - 9 = (2x-3)(2x+3)
f) 16x^2 - 25 = (4x-5)(4x+5)
g) 4x^2 - 25 = (2x-5)(2x+5)
h) 36 - 25x^2 = (6-5x)(6+5x)
