Question

Giá trị của x thỏa mãn : ^{\(2^x+2^{x+2}=20\)}

Giúp mk mk tick cho

Answer 1

Ta có: \(2^x+2^{x+2}=20\)

\(\Rightarrow\) \(2^x+2^x.4=20\)

\(\Rightarrow\) \(2^x\left(1+4\right)=20\)

\(\Rightarrow2^x.5=20\)

\(\Rightarrow2^x=20:5\)

\(\Rightarrow\) \(2^x=2^2\)

\(\Rightarrow x=2\)

Vậy \(x=2.\)

Answer 2

\(2^x+2^{x+2}=20\)

Answer 3

\(2^x+2^{x+2}=20\)

\(\Rightarrow2^x+2^x\times2^2=20\)

\(\Rightarrow2^x+2^x\times4=20\)

\(\Rightarrow2^x\times\left(1+4\right)=20\)

\(\Rightarrow2^x\times5=20\)

\(\Rightarrow2^x=20\div5\)

\(\Rightarrow2^x=4\)

\(\Rightarrow2^x=2^2\)

\(\Rightarrow x=2\)

Vậy \(x=2\) thì thỏa mãn đề bài.

Answer 4

\(2^x+2^{x+2}=20\)

\(\Rightarrow2^x\left(1+2^2\right)=20\)

\(\Rightarrow2^x.5=20\)

\(\Rightarrow2^x=4\)

\(\Rightarrow2^x=2^2\)

\(\Rightarrow x=2\)

Vậy....

Answer 5

Ta có : \(2^x+2^{x+2}=2^2+2^{2 +2}\)
Suy ra x=2