如果直線ax+2y+2=0與直線3x-y-2=0平行,那麼實數a等於() A. -6B. -3C.−32D. 23

如果直線ax+2y+2=0與直線3x-y-2=0平行,那麼實數a等於() A. -6B. -3C.−32D. 23

∵直線ax+2y+2=0與直線3x-y-2=0平行,∴它們的斜率相等,∴−a2=3,∴a=-6.故選A.