Respuestas

2012-05-23T06:59:12+02:00

(x+1)(2x-1)=2x^2+x-1
(x²-4)(x²+4)=x^4-16
(3a-b)(3a+b)=9a²-b²
(2a²+5)(2a²-5)=4a^4-25