Question

\(3^x+5.3^{x+2}=414\)

Answer 1

Bài làm:

Ta có: \(3^x+5.3^{x+2}=414\)

\(\Leftrightarrow3^x\left(1+5.3^2\right)=414\)

\(\Leftrightarrow3^x.46=414\)

\(\Leftrightarrow3^x=9=3^2\)

\(\Rightarrow x=2\)

Answer 2

3^x + 5 . 3^{x + 2} = 414

<=> 3^x + 5 . 3^x . 3² = 414

<=> 3^x ( 1 + 45 ) = 414

<=> 3^x . 46 = 414

<=> 3^x = 9

<=> 3^x = 3²

<=> x = 2

Answer 3

3^x + 5.3^x+2 = 414

<=> 3^x.1 + 5.3^x.3² = 414

<=> 3^x( 1 + 5.3² ) = 414

<=> 3^x.46 = 414

<=> 3^x = 9

<=> 3^x = 3²

<=> x = 2

Answer 4

Bài làm 

\(3^x+5.3^{x+2}=414\Leftrightarrow3^x\left(1+5.3^2\right)=414\)

\(\Leftrightarrow3^x.41=414\Leftrightarrow3^x=9\Leftrightarrow3^x=3^2\Leftrightarrow x=2\)

Answer 5

\(3^x\)\(+5.3^{x+2}\)\(=414\)

\(\Leftrightarrow\)\(3^x\)\(\left(1+5.3^2\right)\)\(=414\)

\(\Leftrightarrow3^x.46=414\)

\(\Leftrightarrow3^x=9\)

\(\Leftrightarrow3^x=3^2\)

\(\Rightarrow x=2\)