已知m满足2m-1除3等于3,k、n满足（2k+1)²+根号91+7n等于0,求3的立方根m²-3n

(2m-1)/3=3
2m-1=3*3
2m=10
m=5
（2k+1)²+根号(91+7n)=0
2k+1=0 k=-1/2
91+7n=0 n=-13
3的立方根(m²-3n)-根号k²
=3的立方根(5^2+13*3)-根号(-1/2)^2
=3的立方根64-根号1/4
=4-1/2
=7/2