Question

Tìm x biết 5^x + 5^{x + 2} = 650

Answer 1

5^x + 5^x+2 = 650

5^x + 5^x * 5^2= 650

5^x (1 + 5^2) = 650

5^x * 26 = 650

5^x = 650: 26

5^x = 25

5^x = 5^2

=> x=2

Answer 2

\(5^x+5^{x+2}=650\)

\(\Leftrightarrow5^x\left(1+5^2\right)=650\)

\(\Leftrightarrow5^x.26=650\)

\(\Leftrightarrow5^x=25\)

\(\Leftrightarrow5^x=5^2\)

\(\Rightarrow x=2\)

Answer 3

\(5^x+5^{x+2}=650\)

=> \(5^x+5^x.25=650\)

=>\(5^x.\left(1+25\right)=650\)

=> \(5^x.26=650\)

=>\(5^x=25=>x=2\)