(1)计算lg27+lg8?lg1000lg1.2 &

2025-06-29 05:59:39
推荐回答(1个)
回答1:

(1)原式=

lg3
3
2
+lg23?lg10
3
2
lg
12
10
=
3
2
lg3+3lg2?
3
2
lg(3×4)?1
=
3
2
(lg3+2lg2?1)
lg3+2lg2?1
=
3
2

(2)由18b=5得:log185=b,
log365=
log185
log1836
=
log185
log18(4×9)
=
log185
2log182+log189
=
log185
2(1?log189)+log189
=
b
2?a