數學......

2006-12-11 5:18 am

1元1次方程

peter買了侮枚$5的郵票y枚,又買了侮枚2.5的郵票(y+2)枚,如果他用左$50
問y的值

回答 (5)

2006-12-11 5:28 am

✔ 最佳答案

Y X 5 + (Y+2) X 2.5 = 50
可寫成: 5Y + 2.5Y + 5 = 50
即: 7.5Y = 50 - 5
答案: Y = 45/7.5 = 6

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2006-12-11 5:27 am

5y + 2.5(y+2) = 50
5y + 2.5y + 5 = 50
7.5y = 45
y = 6

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2006-12-11 5:26 am

50=5y+2.5(y+2)
自己計下!

答案係y=6

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2006-12-11 5:26 am

50 = 5y + 2.5 (y+2)
50 = 7.5 y + 5
7.5 y = 45
y = 6

參考: myself

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2006-12-11 5:25 am

peter買了侮枚$5的郵票y枚 - cost = 5y

又買了侮枚2.5的郵票(y+2)枚 - cost = 2.5(y+2)

如果他用左$50 - total cost = 50

5y + 2.5(y+2) = 50

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