我来解答一下吧:把已知条件变为:x^(0.5)+x^(-0.5)=3
首先解分母:x^2+x^(-2)+3=[x+x^(-1)]^2-2+3=[x+x^(-1)]^2+1
而x+x^(-1)=[x^(0.5)+x^(-0.5)]^(2)-2=7
所以由上式可得分母的值:7^(2)+1=50
下面再来做分子:x^(3/2)+x^(-3/2)=[x^(0.5)]^3+[x^(-0.5)]^3=[x^(0.5)+x^(-0.5)][x+x^(-1)-1]=3*6=18
所以分子为20,所以最后原式的值:0.4即5分之2