教育學術中小學校 - 數學正負數問題

2006-12-15 7:18 am

請問以下題目的解釋:

(-2) x 2 = - (2 x 2) = - 4 點解會變負數

(-2) x 2 x (-2) = 2 x 2 x 2 = 8 點解會變正數

(-2) x 2 x (-2) x (-2) = - (2 x 2 x 2 x 2) = -16 點解會變負數

(-2) x 2 x (-2) x (-2) x (-2) = 2 x 2 x 2 x 2 x 2 = 32 點解會變正數

回答 (3)

kam chi

2006-12-15 7:46 am

✔ 最佳答案

a(-2) x 2 = - (2 x 2) = - 4

b(-2) x 2 x (-2) = 2 x 2 x 2 = 8
c(-2) x 2 x (-2) x (-2) = - (2 x 2 x 2 x 2) = -16

(d-2) x 2 x (-2) x (-2) x (-2) = 2 x 2 x 2 x 2 x 2 = 32
a果條就係-2乘+2=-4因為負正得負
b..因為-2乘正2變左負但係仲有一個-2 基於負負得正的6係 so=8
私人醒你...正正得正.負負得正..負正得負..正負得負
除法係睇個數就正or負
eg 負2乘正2 負3乘正3 負4乘負5得出黎來正數你自計下

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