Question

（1）计算21+

1

2

log25+lg²5+lg2lg50
（2）化简

3	xy2• xy-1

•

xy

•(xy)-1．

Answer 1

（1）原式=2×2

1

2

log25+lg25+lg2(1+lg5)
=2

5

+lg5(lg2+lg5)+lg2
=2

5

+1
（2）原式=[xy2(xy-1)

1

2

]

1

3

•(xy)

1

2

-1
=x

1

3

y

2

3

|x|

1

6

|y|-

1

6

|x |-

1

2

|y|-

1

2

=x

1

3

|x| -

1

3

=

1，x＞0 -1，x＜0

．