The equation of the chord of he circle $${x^2} + {y^2} - 4x = 0$$ whose midpoint is (1, 0) is

The circles x² + y² $$-$$ 10x + 16 = 0 and x² + y² = a² intersect at two distinct points if

For the two circles x² + y² = 16 and x² + y² $$-$$ 2y = 0 there is/are

The straight line x + y $$-$$ 1 = 0 meets the circle x² + y² $$-$$ 6x $$-$$ 8y = 0 at A and B. Then the equation of the circle of which AB is a diameter is