Thứ Tư, 10 tháng 7, 2013

The coordinates of the points.

If the family of lines x(a + 2b) + y(a + 3b) = a + b passes through the point for all values of a and b, then the coordinates of the points are ?
  1. (2, 1) 
  2. (2, – 1) 
  3. (– 2, 1)
  4. None of these