当(a-b)/b=2/3时,则a/(b-2a)=?

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当(a-b)/b=2/3时,则a/(b-2a)=?
当(a-b)/b=2/3时,则a/(b-2a)=?

当(a-b)/b=2/3时,则a/(b-2a)=?

(a-b)/b=2/3
得:
3(a-b)=2b
3a-3b=2b
a=5/3 b
∴a/(b-2a)
=(5/3 b)/(b-2*5/3 b)
=(5/3 b)/(-7/3 b)
=-5/7
望采纳,O(∩_∩)O谢谢

(a-b)/b=2/3
3a-3b=2b
3a=5b
a=5b/3
a/(b-2a)
=(5b/3)/(b-2×5b/3)
=-5/7

∵ (a - b)/ b = 2 / 3
∴ 2 b = 3(a - b)
2 b = 3 a - 3 b
5 b = 3 a
a = (5 / 3)b
∴ a / (b - 2 a)= (5 / 3) b / (b - 2 × (5 / 3) b)= (5 / 3) b / (- 7 / 5) b= - 5 / 7

(a-b)/b=2/3时,
a-b : b = 2:3
a :b = 2+3 : 3 = 5 : 3
设a = 5k b =3k
则a/(b-2a)
= 5k / ( 3k-10k)
= 5k / -7k
= -5/7


(a-b)/b=2/3可得2b=3(a-b)
即a=5/3b 带入a/(b-2a)即可得到答案-5/7

-5/7
由已知得a=5b/3
带入第二个式子得-5/7