Răspuns :
a) x^2+4x+4-25=0
x^2+4x-21=0
∆=16+84
√∆=10
1. x= (-4-10) :2 = -7
2. x = (-4+10):2= 3
b)
x^2+6x+9=0
(x+3)^2=0
x= -3
c)
x^2+4x+4=-1
x^2+4x+5=0
∆= 16-20
√∆= {multimea vida (adica nu are solutii)}
d)
x^2+4x+4=0
∆=16-16
√∆ = 0
x= -2
e)
x^2+10x+16=0
∆=100-64
√∆=6
1. x=(-10-6):2= -8
2.x= (-10+6):2 = -2
f)
x^2+10x+25=0.
(x+5)^2=0
x= -5
Gata, succes in matematica!!!