... x2 6x + = B x2 + = C 2x2 x = D x2 + x + = Cõu : Gi x1, x2 l nghim ca phng trỡnh : 2x 3x = ta cú 5 3 A x1+ x2 = - ; x1x2 = B x1+ x2 = ; x1x2 = 2 2 5 C x1+ x2 = ; x1x2 = D x1+ x2 = ; x1x2 ... x1x 2m 0 ,25 Vỡ x1 ; x2 l di hai cnh ca mt tam giỏc vuụng cú cnh huyn bng 12 x1 x 12 x1 x 2x1x 12 2 Do ú: 2( m 1) 2. 2m 12 4m 8m 4m 12 m 4m2 4m m m m 0 ,25 0 ,25 Vy ... iu kin m x1 + x2 = 0 ,25 x1 x2 = 2m Ta cú: x 12 + x 22 + x1 + x2 12 ( x x ) x x x x 12 m 2 0 ,25 0 ,25 Vy m Bi (4,0 ) 0 ,25 Cõu 1: (1,0) V (P) ỳng 0,5 V (d) ỳng 0,5 Cõu 2: (1,0) Phng trỡnh...