Respuesta :
x^2+9x+20= 0
(x+4)(x+5)= 0
x+4= 0
Move +4 to other side. Sign changes from +4 to -4.
x+4-4= 0-4
x= -4
x+5= 0
Move +5 to other side. Sign changes from +5 to -5.
x+5-5= 0-5
x= -5
Answer : x= -5, x= -4
x^2+9x+20= 0
(x+4)(x+5)= 0
x+4= 0
Move +4 to other side. Sign changes from +4 to -4.
x+4-4= 0-4
x= -4
x+5= 0
Move +5 to other side. Sign changes from +5 to -5.
x+5-5= 0-5
x= -5
Answer : x= -5, x= -4
