Solve for the value of x.

Can someone me i’m confused. will give brainliest and a whole bunch of points

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

The area of square garden is 300m squared. how long is the diagonal?