问题
解答题
(1)若x
(2)化简
|
答案
(1)∵x
+x-1 2
=3,1 2
∴x+x-1=9-2=7,
x2+x-2=49-2=47,
∴x
+x-3 2
=(x3 2
+x-1 2
)(x+x-1-1)=3×6=18,1 2
∴
=x
+x-3 2
-33 2 x2+x-2-2
=18-3 47-2
.1 3
(2)∵a>0,b>0,
∴a3b2 3 ab2 (a
b1 4
)4•1 2 3 b a
=a
b•[(ab2)3 2
]1 3 1 2 ab2•(
)b a 1 3
=a
b•a3 2
b1 6 1 3 a
b2 3 7 3
=a
b10 6 4 3 a
b2 3 7 3
=
.a b