问题 解答题
(1)计算:2log32-log3
32
9
+log38-25log53
(2)已知x=27,y=64.化简并计算:
5x-
2
3
y
1
2
(-
1
4
x-1y
1
2
)(-
5
6
x
1
3
y-
1
6
)
答案

(1)2log32-log3

32
9
+log38-25log53

=log34-log3

32
9
+log38-52log53

=log3(4×

9
32
×8)-5log59

=log39-9=2-9=-7.

(2)∵x=27,y=64,

5x-
2
3
y
1
2
(-
1
4
x-1y
1
2
)(-
5
6
x
1
3
y-
1
6
)

=

5x-
2
3
y
1
2
(-
1
4
)×(-
5
6
x-1+
1
3
×y
1
2
-
1
6

=

5x-
2
3
y
1
2
5
24
×x-
2
3
×y
1
3

=24y 

1
6

=24×(26 

1
6

=48.

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