用matlab解吧,答案为:
x1=11/(18*((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3)) + ((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3) - 1/3
x2= - 11/(36*((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3)) - ((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3)/2 - 1/3 - (3^(1/2)*(11/(18*((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3)) - ((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3))*i)/2
x3=- 11/(36*((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3)) - ((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3)/2 - 1/3 + (3^(1/2)*(11/(18*((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3)) - ((151^(1/2)*216^(1/2))/216 + 26/27)^(1/3))*i)/2