Find the Points of Intersection of two Circles

Find the points of intersection of the circles given by their equations : x minus 2 squared plus y minus 3 squared is equal to 9 and x minus 1 squared plus y plus 1 squared is equal to 16. . Solution : We first expand all the squares in both equations. Multiply all terms in the first equation by -1 to obtain an equivalent system of equations.The second equation is unchanged.