Help me to solve this question please~

Q: Find the standard equation of the circle [which means in the form of $\displaystyle (x-a)^2+(y-b)^2=r^2$] that passing through the point $\displaystyle (-3,1)$ and containing the points of intersection of the circles $\displaystyle x^2+y^2+5x=1$ and $\displaystyle x^2+y^2+y=7$.

When i looking for the intersection point of the 2 circles, i found that both of their (x,y) coordinate are irrational numbers (I'm forced to use the quadratic formula to solve it). After that, it become more and more complicated in further solving... And the answer came out, WRONG! Congratulation to myself. I wonder did anyone figure out how to solve it? I can't find another point to form the two bisectors of their chords, in order to get the coordinate of the center, I need to find the intersection point of the two bisectors. So anyone please help me!