已知 a+b+c=2023a + b + c = 2023a+b+c=2023,ax2−yz=by2−xz=cz2−xy\frac{a}{x^2 - yz} = \frac{b}{y^2 - xz} = \frac{c}{z^2 - xy}x2−yza=y2−xzb=z2−xyc,x+y+z≠0x + y + z \not= 0x+y+z=0,求 ax+by+czx+y+z\frac{ax + by + cz}{x + y + z}x+y+zax+by+cz 的值。 本人是初二蒟蒻,听说跟立方有关,不知是何物,求助各位大佬