问题
解答题
计算: (1)lg700-lg56-3lg
(2)计算2-(
|
答案
(1)原式=lg
+20×(lg700 56×(
)31 2
)2+20 2
=lg100+20×1+7 7log72
=2+20+7 2
=7 2
;51 2
(2)原式=
+1 2
+(1 2
+1)-1-(23)2
=22 3
-4.2
计算: (1)lg700-lg56-3lg
(2)计算2-(
|
(1)原式=lg
+20×(lg700 56×(
)31 2
)2+20 2
=lg100+20×1+7 7log72
=2+20+7 2
=7 2
;51 2
(2)原式=
+1 2
+(1 2
+1)-1-(23)2
=22 3
-4.2