问题 解答题

计算

(1)(2a22

(2)(a2b)3

(3)(-3a)3(a24

(4)(a23+5a3•a3-(2a23

(5)0.1255×85

(6)0.252007×42009

(7)2(y32•y3-(3y32+(5y)2•y7

答案

(1)(2a22=4a4

(2)(a2b)3=a6b3

(3)(-3a)3(a24=-27a3•a8=-27a11

(4)(a23+5a3•a3-(2a23=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(y32•y3-(3y32+(5y)2•y7=2y6•y3-9(y32+25y2•y7=2y9-9y6+25y9=27y9-9y6

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