請用乘法公式算
1. 9×(-222)-9×333+(-9)×445
2. 2001×2002-1999×2004
乘法公式×2不會的急求解?
2016-07-28 1:00 pm
回答 (2)
2016-07-28 1:57 pm
✔ 最佳答案
1.9*(-222) - 9*333 + (-9)*445
= 9*111*(-2) - 9*111*3 - 9*( 111*4 + 1 )
= 9*111*( - 2 - 3 - 4 ) - 9
= 999*(-9) - 9
= ( 1000 - 1 )*(-9) - 9
= 1000*(-9) + 9 - 9
= - 9000 ..... Ans
2.
令 k = 2000
原式
= (k+1)(k+2) - (k-1)(k+4)
= k^2 + 3k + 2 - ( k^2 + 3k - 4 )
= 6 ..... Ans
2016-07-28 3:33 pm
1.
9×(-222)-9×333+(-9)×445
=-9000
2.
2001×2002-1999×2004
=6
9×(-222)-9×333+(-9)×445
=-9000
2.
2001×2002-1999×2004
=6
收錄日期: 2021-04-18 15:20:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160728050026AAVwZnN