Question

tìm x biết:

\(3^x+3^{x+1}+3^{x+2}=117\)

Answer 1

3^x  + 3^x+1 + 3^x+2  = 117

=> 3^x  + 3¹ + 3² + 3^x  + 3^x = 117

=> 3^x  . ( 3¹ + 3²  + 1 ) = 117

=> 3^x . 13 = 117

=> 3^x = 117 : 13

=> 3^x = 9

=> 3^x = 3²

^{=> x = 2}

 

Answer 2

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Answer 3

 

\(3^x\left(1+3+3^2\right)=117\)

\(3^x.13=117\)

\(3^x=9=3^2\)

\(x=2\)