问题
解答题
求值: (1)0.16-
(2)(lg2)2+lg2•lg50+lg25. |
答案
(1)0.16-
1 |
2 |
3 |
4 |
2 |
=
5 |
2 |
1 |
2 |
=10.
(2)(lg2)2+lg2•lg50+lg25
=(lg2)2+lg2(lg2+2lg5)+2lg5
=2(lg2)2+2lg2lg5+2lg5
=2lg2(lg2+lg5)+2lg5
=2lg2+2lg5
=2.
求值: (1)0.16-
(2)(lg2)2+lg2•lg50+lg25. |
(1)0.16-
1 |
2 |
3 |
4 |
2 |
=
5 |
2 |
1 |
2 |
=10.
(2)(lg2)2+lg2•lg50+lg25
=(lg2)2+lg2(lg2+2lg5)+2lg5
=2(lg2)2+2lg2lg5+2lg5
=2lg2(lg2+lg5)+2lg5
=2lg2+2lg5
=2.