2X^2 + 4X - 6 = 2 * ( X^2 + 2X - 3 ) = 2 * ( X - 1 ) * ( X + 3 ) D = 4 + 12 = 16 ; √ D = 4 X1 = ( - 2 + 4 ) : 2 = 1 X2 = ( - 2 - 4 ) : 2 = - 3 -------------------------------X^2 - 9 = ( X - 3 )*( X + 3 )--------------------------------Сокращаем на ( Х + 3 ) числитель и знаменатель получаем( 2 * ( X - 1 )) /( X - 3 ) ; X ≠ 3 ; X ≠ - 3 ----------------------------------( 2X - 2 ) = 1 * ( X - 3 ) 2X - 2 = X - 3 X = - 1