1.(-9)^7x(-27)^(-4)
2.6^(-25)x12^12÷18^(-10)
F.3maths ....
2012-09-30 7:38 pm
回答 (2)
2012-10-01 3:00 am
✔ 最佳答案
1.(－9)^7*(－27)^(－4)=－(9^7)/(27^4)
=－3^14/3^12
=－9
2.6^(－25)*12^12÷18^(－10)
=(1/6^25)*(12^12)*(18^10)
=12^12*18^10/6^25
=[(2^2)*3]^12*[2*(3^2)]^10/[(2^25)*(3^25)]
=[(2^24)*(3^12)]*[(2^10)*(3^20)]/[(2^25)*(3^25)]
=2^(24+10－25)*3^(12+20－25)
=(2^9)*(3^7
=512*2187
=1119744
2012-09-30 8:52 pm
唔好意思,你條題目唔多清楚
收錄日期: 2021-04-13 19:00:43
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120930000051KK00169