Please guys I really need you're help

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

What is the average diastolic blood pressure for adults