Hint: Substitute either x^2 or y^2 into the other equation to get a quadratic in terms of one variable and solve.
Verify that the circles x2+y2 = 25 and (x−5)2+(y−10)2= 50 intersect at A = (4, 3).
Find the size of the acute angle formed at A by the intersecting circles. You will ﬁrst have to decide what is meant by the phrase the angle formed by the intersecting circles
Angle formed by two curves is the angle between the tangents to the curves at the point of intersection. First find the point of intersection and then the slopes of tangents and proceed further. Angle between two lines with slopes m and n is given by (m-n)/(1+mn)