\(5^x+5^{x-1}=750\)
\(\Rightarrow5^x+5^x.\frac{1}{5}=750\)
\(\Rightarrow5^x.\left(1+\frac{1}{5}\right)=750\)
\(\Rightarrow5^x.\frac{6}{5}=750\)
\(\Rightarrow5^x=750:\frac{6}{5}\)
\(\Rightarrow5^x=625\)
\(\Rightarrow5^x=5^4\)
\(\Rightarrow x=4\)
Vậy \(x=4\)
Ta có : 5x + 5x - 1 = 750
\(\Rightarrow\) 5x + 5x - 1 = 625 + 125
\(\Rightarrow\) 5x + 5x - 1 = 54 + 53
\(\Rightarrow\) x = 4
Vậy x = 4
\(5^x+5^{x-1}=750\)
\(\Rightarrow\)\(5^x+5^x.\dfrac{1}{5}=750\)
\(\Rightarrow\)\(5^x.\left(1+\dfrac{1}{5}\right)=750\)
\(\Rightarrow\)\(5^x.\dfrac{6}{5}=750\)
\(\Rightarrow\)\(5^x=750:\dfrac{6}{5}=625\)
\(\Rightarrow\)\(5^x=5^4\)
Vậy, x = 4
5x + 5x-1 = 750
\(\Rightarrow\) 5x + 5x . \(\dfrac{1}{5}\) = 750
\(\Rightarrow\) 5x . \(\left(1+\dfrac{1}{5}\right)\) = 750
\(\Rightarrow\) 5x . \(\dfrac{6}{5}=750\)
\(\Rightarrow\) 5x = 750 : \(\dfrac{6}{5}\)
\(\Rightarrow\) 5x = 750 x \(\dfrac{5}{6}\)
\(\Rightarrow\) 5x = 625
\(\Rightarrow\) 5x = 54
\(\Rightarrow\) x = 4
