How do i do this i need so i don’t fail

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

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that

Can someone me and explain..will award brainlest!