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How do i solve (e^x+7)/(3e^-x+5)=3 ? The solution should be in the form of: x = ln a

e(ex+7)(3×ex+5)=3

 Aug 3, 2015

Best Answer 

 #1
avatar+118696 
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(ex+7)(3ex+5)=3(ex+7)÷(3ex+5)=3(ex+7)÷(3ex+5)=3(ex+7)÷(3+5exex)=3(ex+7)×(ex3+5ex)=3(ex+7)×ex=3(3+5ex)(ex)2+7ex=9+15ex(ex)28ex9=0

 

lety=exy28y9=0(y9)(y+1)=0y=9ory=1ex=9orex=1ex>0$forallrealxso$ex=9x=ln9x=ln32x=2ln3

.
 Aug 3, 2015
 #1
avatar+118696 
+5
Best Answer

(ex+7)(3ex+5)=3(ex+7)÷(3ex+5)=3(ex+7)÷(3ex+5)=3(ex+7)÷(3+5exex)=3(ex+7)×(ex3+5ex)=3(ex+7)×ex=3(3+5ex)(ex)2+7ex=9+15ex(ex)28ex9=0

 

lety=exy28y9=0(y9)(y+1)=0y=9ory=1ex=9orex=1ex>0$forallrealxso$ex=9x=ln9x=ln32x=2ln3

Melody Aug 3, 2015

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