it is simple for you but diffcult to me unforturnelty hope you can teach me
(4^2x-y)=32 find the value of (8^x+2y)=(1/32)
1 simple maths question
2009-10-28 5:06 am
回答 (1)
2009-10-28 8:16 am
✔ 最佳答案
4^(2x-y) = 32 ... (1)8^(x+2y) = 1/32 ... (2)
(1) => (2^2)^(2x - y) = 2^5
2^(4x - 2y) = 2^5
4x - 2y = 5
12x - 6y = 15 ... (3)
(2) => (2^3)^(x + 2y) = 2^(-5)
2^(3x + 6y) = 2^(-5)
3x + 6y = -5 ... (4)
(3) + (4) => 12x + 3x = 10
15x = 10
x = 2/3
Sub into (4), 3(2/3) + 6y = -5
2 + 6y = -5
6y = -7
y = -7/6
收錄日期: 2021-04-23 23:18:54
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https://hk.answers.yahoo.com/question/index?qid=20091027000051KK01430