Anyone know how to do this?

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

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')