先化简,再求值:3根号a^3b/6ab^2,其中丨a+根号3丨+根号b-6=0
问题描述:
先化简,再求值:3根号a^3b/6ab^2,其中丨a+根号3丨+根号b-6=0
答
|a+√3|+√(b-6)=0 两个非负数的和为0,这两个非负数都等于0
a+√3=0,b-6=0
a=-√3,b=6
原式=3√[a³b/(6ab²)] a﹤0,b﹥0
=3√[a²b/(6b²)]
=3√[a²×6b/(6b)²]
=3×(-a)×1/(6b)×√(6b)
=-a√(6b)/(2b)
=√3×√(6×6)/(2×6)
=(6√3)/12
=(√3)/2