Post date: Jan 26, 2016 4:55:2 PM
(x-5)(3x+1)=0
10 x2 + 31 x + 21 = 0
21 x2 + 31 x + 10 = 0
5 x2 - 31 x + 42 = 0
es 3 e 4 pag 365
es 9 e 10 pag 367