Question

\(5^{x+1}+5^{x+2}=750\)

Answer 1

5^{x + 1} + 5^{x + 2} = 750

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

=> 5^{x + 1} = 750 : 6

=> 5^{x + 1} = 125

=> 5^{x + 1} = 5²

=> x + 1 = 2

=> x = 1

Answer 2

5^x+1 + 5^x+2 = 750

5^x+1 + 5^x+1 . 5 = 750

5^x+1 ( 1 + 5 ) = 750

5^x+1 = 750 : 6 = 125 = 5³

<=> x + 1 = 3

<=> x = 2

Vậy x = 2

Answer 3

5^x+1 + 5^x+2 = 750

5^x.(5+25) = 750

5^x.30 = 750

5^x = 25 = 5²

=> x = 2

Answer 4

\(5^{x+1}+5^{x+2}=750\)

\(\Leftrightarrow5^x.5+5^x.5^2=750\)

\(5^x.\left(5+5^2\right)=750\)

\(5^x.30=750\)

\(5^x=25\)

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

\(\Leftrightarrow x=\pm2\)

Answer 5

5^x+1 + 5^x+2 = 750

5^x (5 + 5²) = 750

5^x (5+25) = 750

5^x . 30= 750

5^x =750 : 30

5^x = 25

5^x = 5²

=> x =2

Vậy x = 2