計算
(1)(2a2)2
(2)(a2b)3
(3)(-3a)3(a2)4
(4)(a2)3+5a3•a3-(2a2)3
(5)0.1255×85
(6)0.252007×42009
(7)2(y3)2•y3-(3y3)2+(5y)2•y7
解:(1)(2a2)2=4a4;
(2)(a2b)3=a6b3;
(3)(-3a)3(a2)4=-27a3•a8=-27a11;
(4)(a2)3+5a3•a3-(2a2)3=a6+5a6-8a6=-2a6;
(5)0.1255×85=(0.125×8)5=15=1;
(6)0.252007×42009=0.252007ו42007×42=(0.25×4)2007×16=1×16=16;
(7)2(y3)2•y3-(3y3)2+(5y)2•y7=2y6•y3-9(y3)2+25y2•y7=2y9-9y6+25y9=27y9-9y6.
分析:(1)(2)(3)按冪的乘方、同底數(shù)冪的運算法則計算;
(4)(7)先按冪的乘方、同底數(shù)冪的運算法則計算,再合并同類項;
(5)用積的乘方的逆運算計算;
(6)用積的乘方、同底數(shù)冪的逆運算計算.
點評:此題考查冪的運算在整式運算和有理數(shù)運算中的應(yīng)用,掌握法則的同時,要靈活應(yīng)用.