=(3根号2）^2-1^2-(3倍根号2）^2+6倍根号2-1
=18-1-18+6倍根号2-1
=6呗根号2
-2
=X/
X(X^2-1)-
1/
(2X^2
-2)
=1/(X^2-1)-1/2(X^2-1)
=1/
2(X^2-1)
前面=((A+B)^2-(A-B)^2)/
(A+B)^2*(A-B)^2=4AB/
（A^2-B^2)^2
后面式子=(A+B+A-B)/(A^2-B^2)=2A
/
(A^2-B^2)
相除消去后=2B/(A^2-B^2)
完毕
对的话请采纳
谢啦
2倍根号27÷根号2分之3-(2倍根号2-1)²
=
6倍根号3
÷根号2分之3-(2倍根号2-1)²
=
6倍根号3
÷2分之根号6
-(2倍根号2-1)²
=
12根号2分之1
-(2倍根号2-1)²
=
6倍根号2
-(2倍根号2-1)²
=
6倍根号2
-(9
-
4倍根号2)
=
-9
+10根号2
