Find the value of x of this triangle

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

Use the distributive law to multiply. 3(4x + 5y + 6)

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)