用平方差或完全平方展開
(3x^2+2y)(-3x^2c+2y)
(4m+7)^2
(6x-5y)^2
(9-pq)^2
(3x+1/2)^2
求下列各數的值
22.5^2-7.5^2
1.003^2
999^2
總複習恆等式
2010-10-15 4:26 am
回答 (1)
2010-10-15 4:47 am
✔ 最佳答案
(3x^2+2y)(-3x^2c+2y)<---write wrong?(4m+7)^2
=16m^2+56m+49
(6x-5y)^2
=36x^2-60xy+25y
(9-pq)^2
=81-18pq+p^2*q^2
(3x+1/2)^2
=9x^2+3x+0.25 (0.25=1/4)
求下列各數的值
22.5^2-7.5^2
=(22.5-7.5)(22.5+7.5)
=15*30
=450
1.003^2
=(1+0.003)^2
=1+2.006+9.0 × 10^-6
=3.006009
999^2
=(1000-1)^2
=1000000-2002+1
=997999
參考: Google 計算機的更多資料
收錄日期: 2021-04-23 23:25:51
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101014000051KK01205