С(-1,0) и D(2,-4) равна 58.
[m]AM^2+BM^2+CM^2+DM^2=58[/m]
[m]\underbrace{(x-3)^2+(y-0)^2}_{AM^2}+\underbrace{(x-0)^2+(y-4)^2}_{BM^2}+\underbrace{(x-(-1))^2+(y-0)^2}_{CM^2}+\underbrace{(x-2)^2+(y-(-4))^2}_{DM^2}=58[/m]
[m](x-3)^2+y^2+x^2+(y-4)^2+(x+1)^2+y^2+(x-2)^2+(y+4)^2=58[/m]