A) 2
B) 1
C) 3
D) 0
Correct Answer: C
Solution :
We have, \[\frac{10}{3}\times {{3}^{x}}-{{3}^{x-1}}=81\] \[\Rightarrow 10\times {{3}^{x-1}}-{{3}^{x-1}}=81\] \[\Rightarrow {{3}^{x-1}}(10-1)=81\Rightarrow {{3}^{x-1}}=81\] \[\Rightarrow {{3}^{x-1}}=\frac{81}{9}=9\Rightarrow {{3}^{x-1}}={{3}^{2}}\] On comparing, we get \[x-1=2\Rightarrow x=2+1=3\]You need to login to perform this action.
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