1. The equation of a circle is given by x^2+y^2-10x-8y+16=0. Find the x-intercept(s) and the y-intercept(s) of the circle.

2. The equation of a circle is given by x^2+y^2-6x-4y-12=0. Find the equation of the straight line joining the orgin to the circle.

3. Find the equation of the diameter passing through the point (5,1) on the circle x^2+y^2+4x-2y-11=0.

4. One end of a diameter of the circle C: x^2+y^2-6x-4y-12=0 is(-1,-1). Find the coordinates of the other end.

2.呢度唔係好明
   x^2+y^2-6x-4y-12=0
  (x^2-6x) + (y^2-4y) - 12 = 0.