Could someone show me how to work out these please

1. The circle x^2(y+3)^2=25 meets the x axis at p and q, find the coordinates of p and q?

2. The points A(7,4) B(8,-7) and C(-4,3) lie on a circle. Find the equation of the circle?

3. Find the equation of the tangent at the point (3,1) on the circle

x^2+y^2-4x+10y-8=0

Thanks for your help