@sweetsh - thanx a lot   

@angel - okk...so lets try the next sum
U onto Q 
take any 2 co-ordinates of triangle U i.e = (-6,2) and (0,2) 
arrange them vertically o form a 2 by 2 matrix 
(-6  0)
(2   2)
now let say the unknown matrix of transformation is 
(a  b)
(c  d)
so it implies that when you multiply the co-ordinates of U with the matrix of transformation, you get the co-ordinates of the image i.e triangle Q...(look at the corresponding co-ordinates of U in Q)
you can see that the point (-6,2) is mapped onto (-6,4) and (0,2) to (0,4)
soo the equation is 
(-6  0)  *   (a  b)  = (-6  0) 
(2   2)       (c  d)     (4   4)
if you take (-6  0)
                (2   2) to other side then it becomes the inverse...
so you multiply 
(-6  0)                            (-6  0)
(4   4) with the inverse of  (2   2)
therefore u get the answer (1  0)
                                     (0  2)