Respuestas

2013-08-29T22:33:15+02:00
 7x^{3} +3x^{2} +28x^{1} +12=
( 7x^{3} +28x^{1} )+(3x^{2} +12)=
7x( x^{2} +4)+3( x^{2} +4)=
(7x+3)+( x^{2} +4)=
(7x+3)(( x+2^{)2}