If 3a+7b-4c=127.5, find the values of a,b and c.
更新1:
我計到a=75，b=262.5 , c=210,但最後驗算出來嘅ratio唔係10:15:21
rate and ratio?
回答 (2)
2016-06-14 4:04 pm
✔ 最佳答案
a : b : c = 10 : 15 : 21設 a = 10k, b = 15k 及 c = 21k
3a + 7b - 4c = 127.5
3(10k) + 7(15k) - 4(21k) = 127.5
30k + 105k - 84k = 127.5
51k = 127.5
k = 2.5
a = 10(2.5) = 25
b = 15(2.5) = 37.5
c = 21(2.5) = 52.5
2016-06-14 4:23 pm
哦。。。我明白你意思喇，thank you
收錄日期: 2021-04-18 15:06:36
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