Question

tim x:

5^x+5^x+1=750

Answer 1

\(5^x+5^{x+1}=750\)

\(5^x=750\)

\(5^x.6=750\)

\(5^x=750:6\)
\(5^x=125\)

\(5^x=5^3\)

\(\Rightarrow x=3\)

Answer 2

5^x + 5^x+1 = 750

<=> 5^x + 5^x . 5 = 750

<=> 5^x.(1+5) = 750

<=> 5^x . 6 = 750 

<=> 5^x = 750 : 6 = 125 = 5^3

=> x = 3