计算:(1)log2748+log212-12log242-1(2)0.027 −13-(-16)-2+2560.75+(13−1)0-3-1.
问题描述:
计算:
(1)log2
+log212-
7 48
log242-11 2
(2)0.027 −
-(-1 3
)-2+2560.75+(1 6
)0-3-1. 1
−1
3
答
(1)log2
+log212-
7 48
log242-11 2
=log2(
×12×
7 48
×
1 42
)1 2
=log22−
=-3 2
.3 2
(2)0.027 −
-(-1 3
)-2+2560.75+(1 6
)0-3-11
−1
3
=0.3-1-36+64+1-
1 3
=32.
答案解析:(1)利用对数的运算法则和运算性质求解.
(2)利用根式与分数指数幂的运算法则求解.
考试点:根式与分数指数幂的互化及其化简运算;有理数指数幂的化简求值.
知识点:本题考查根式、分数指数幂、对数的化简求值,是基础题,解题时要注意运算法则的合理运用.