Răspuns :

a)x^2+10x+25=x^2+14x+49
14x-10x=25-49
4x=-24
x=-6
b)2*(2+2x+4)=24
2*(2x+6)=24
2x+6=24:2
2x+6=12
2x=12-6
2x=6
x=6:2=3
c)x^2-10x+25=0
(x-5)^2=0
x-5=0
x=5