1/a=1/x+1/(y+z+w)
1/b=1/y+1/(x+z+w)
1/c=1/z+1/(x+y+w)
1/d=1/w+1/(x+y+z)
其中a,b,c,d为己知数.
x,y,z,w为末知数.
求解x,y,z,w