= ( x2 - x ) + ( 6x - 6 )=x(x-1)+6(x-1)=(x-1)(x+6)2b, 2x + 3x - 5 = 2x 2 - 2x + 5x - 5 = ( 2x 2 - 2x ) + ( 5x 5)= 2x ( x - 1 ) + 5 ( x - 1 )= ( x - 1 ) ( 2x + 5 )Bài 3Tìm x, biết:a, 5x ( x - 1 ) = x - 1 ; b,2 ( x + 5 ) - x 2 - 5x = 0Trả lời:a, 5x ( x - 1 ) = x - 1 5x ( x - 1 ) - ( x - 1 ) = 0 ( x -[r]