how to get the coordinates of A and B

in The straight line y = x + 3 cuts the circle x +(y -1)= 20 at A and B. a) Determine the coordinates of A and B if the x-value at A is less than at B. b) Determine the length of chord AB. Determine the coordinates of N. the midpoint of AB. Show that ON _ AB if O is the circle centre. Determine the equation of the tangent to the circle at A. If the equation of the tangent at B is v = -0,5.+6, determine the coordinates of C, the point of intersection of the tangents to the circle at A and B