已知x（½）＋x（－½）＝3,计算[x（³／²）＋x（－³／&

[x（½）＋x（－½）]^2=x+1/x+2＝9
x+1/x=7
x²＋x（－²）＋2=49
x²＋x（－²）=47
21=7*3=(x+1/x)(x（½）＋x（－½）)
=[x（³／²）＋x（－³／²）]+[x（½）＋x（－½）]
=[x（³／²）＋x（－³／²）]+3
[x（³／²）＋x（－³／²）]=18
[x（³／²）＋x（－³／²）＋2] ／[x²＋x（－²）＋3]
=20/50=2/5