1) 3x^2 + 2x - 1 = 3( x - 1/3 )( x + 1 )
D = 4 + 12 = 16 = 4^2
X1 = ( - 2 + 4 ) : 6 = 1/3
X2 = ( - 2 - 4 ) : 6 = - 1
2) 2x^2 + x - 1 = 2( x - 1/2 )( x + 1 )
D = 1 + 8 = 9 = 3^2
X1 = ( - 1 + 3 ) : 4 = 1/2
X2 = ( - 1 - 3 ) : 4 = - 1
3) ( 3( x - 1/3 )( x + 1 )) / ( 2( x - 1/2 )( x + 1 )) = ( 3x - 1 ) / ( 2x - 1 )