若实数abc满足a^2+(5+b)^2+根号(c+1)=3(2a-3),求-(2b-c)/a的立方根

a^2+(5+b)^2+√(c+1)=3(2a-3)
a^2+(5+b)^2+√(c+1)=6a-9
a^2-6a+9+(5+b)^2+√(c+1)=0
(a-3)^2+(5+b)^2+√(c+1)=0
∴a-3=0
a=3
5+b=0
b=-5
c+1=0
c=-1
∴-(2b-c)/a
=-[2*(-5)+1]/3
=9/3
=3
∴-(2b-c)/a的立方根为³√3