Question

3(х во 2 степени +2х+1)=0

Answer 1

3 * ( X² + 2X + 1 ) = 0 
3 * ( X + 1 ) * ( X + 1 ) = 0 
X + 1 = 0 
X = - 1 

Answer 2

3(x^2+2x+1)=0, D=1-1=0, x=-1.