Respuesta :

x² +4x  +3 = (x + 3 )( x +1 )

b² +8b +15 = (b + 5 )(b +3 )

x² -12x +35 = ( x - 7 )( x -5)

x² +5x +4 = (x +4 )(x +1)

x² +10x +25 = (x +5 )(x +5) = (x +5)²