计算(1)(0.25)1/2−[−2×(3/7)0]2×[(−2)3]4/3+(2−1)−1−21/2(2)1/2lg32/49−4/3lg8+lg245+(lg2)•lg50+lg25.
问题描述:
计算
(1)(0.25)
−[−2×(1 2
)0]2×[(−2)3]3 7
+(4 3
−1)−1−2
2
1 2
(2)
lg1 2
−32 49
lg4 3
+lg
8
+(lg2)•lg50+lg25.
245
答
(1)原式=[(
)2]1 2
-(-2)2+(-2)4+1 2
-1
-1
2
=
2
-4+16+1 2
+1-
2
=
2
.27 2
(2)原式=lg(
×
32 49
)-lg(2
245
)3 2
+lg2(1+lg5)+lg254 3
=lg(4
)-2lg2+lg2+lg5(lg2+lg5)
10
=2lg2+
-2lg2+lg2+lg51 2
=
+1=1 2
.3 2