數學題 about%

2007-07-19 9:51 pm

朱古力蛋糕一盒,9折較7折貴320元,求價錢?

回答 (3)

2007-07-19 9:58 pm

✔ 最佳答案

朱 x 90% - $320 = 朱 x 70%
90%x - 320 = 70%x
90%x-70%x=320
(90%-70%)x=320
20%x=320
x=320 / 20%
x = 320/
x = 1600
朱古力 = 1600

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2007-07-19 10:07 pm

Let 一盒朱古力蛋糕 be $x

9折朱古力蛋糕 = 0.9x
7折朱古力蛋糕 = 0.7x

0.9x-0.7x = $320
0.2x = $320
x = $320/0.2
x = $1600

一盒朱古力蛋糕 is $1600

參考: me

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2007-07-19 9:55 pm

320 / 0.2 = 1600

1600*0.9 = 1440
1600*0.7 = 1120

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