Explicación paso a paso:
x²+7x+12=0
x +4 ( X + 4 )
x +3 ( x + 3 )
( x + 4 ) = 0 ( x + 3 ) = 0
x = - 4 X = -3
x²+8x+15=0
x +5 ( x + 5 )
x +3 (x + 3 )
(x + 5) = 0 ( x + 3) = 0
x = - 5 x = - 3
x²+5x+6=0
x + 6 ( x + 6 )
x - 1 ( x - 1 )
( x + 6 ) = 0 ( x + 1 ) = 0
x = -6 x = 1
x²+4x+3=0
x +9 ( x + 9 )
x +5 (x + 5 )
(x + 9) = 0 ( x + 5) = 0
x = - 9 x = - 5
Espero y te ayude .
