Question

5^x+5^x+1+5^x+2=31

Answer 1

`5^x + 5^(x+1) + 5^(x+2) = 31`

`=> 5^x + 5^x . 5+ 5^x . 5^2 = 31`

`=> 5^x + 5^x . 5+ 5^x . 25 = 31`

`=> 5^x . (1 + 5 + 25) = 31`

`=> 5^x . 31 = 31`

`=> 5^x  = 1`

`=> 5^x = 5^0`

`=> x = 0`

Vậy ...

Answer 2

\(5^x+5^{x+1}+5^{x+2}=31\)
\(\Rightarrow5^x+5^x.5+5^x.5^2=31\)
\(\Rightarrow5^x.\left(1+5+5^2\right)=31\)
\(\Rightarrow5^x.\left(6+25\right)=31\)
\(\Rightarrow5^x.31=31\)
\(\Rightarrow5^x=31:31\)
\(\Rightarrow5^x=1\)
\(\Rightarrow5^x=5^0\)
\(\Rightarrow x=0\)
Vậy ....