幾條英文代數題 - Ans.fyi 參考答案

幾條英文代數題

[匿名]

2009-10-23 2:41 am

1.The sum of two numbers, A and B, is 33. If 3/5 of A is equal to one half of B, find the two numbers.

2.Thw weight of a cat is 0.3 kg more than 12 times that of a rat, while the weight of a dog is 0.2 kg less than 14 times that of the rat. If the weights of the cat and
the dog are the same,
a.)what weight in kg is the rat?
b.)what weight in kg is the cat?

3.There are some $2 and $1/2 coins in a purse. If the total number of coins is 17 and their total value is $22, find the number og $2and the number of $1/2 coins .

更新1:

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回答 (1)

用戶2053

2009-10-23 2:55 am

✔ 最佳答案

A+B=33

so B = 33-A

(3/5)A = B/2

6A = 5B

6A = 5(33-A)

11A = 165

A = 15
B = 33-15 = 18

2a) Cat = 12Rat + 0.3
Dog = 14Rat - 0.2

Cat = Dog:
12Rat + 0.3 = 14Rat - 0.2

2Rat = 0.5

Rat = 0.25kg

b) Cat = 12(0.25) + 0.3 = 3.3kg

3) Let x be the number of $2 , then total (17 - x) $1/2

Total value = 2x + (1/2)(17 - x) = 22

4x + 17 - x = 44

3x = 27

x = 9

The number of $2 = 9
The number of $1/2 = 17-9 = 8

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