Question

[Lê Văn Phong]

tìm x biết 2^x-1+2^x+2^x+1=112

Answer 1

[Kiều Nam Khánh]

Đáp án:

$2^{x-1}+2^x+2^{x+1}=112$

$\Rightarrow 2^x:2+2^x+2^x.2^1=112$

$\Rightarrow 2^x.\frac{1}{2}+2^x+2^x.2=112$

$\Rightarrow 2^x.(\frac{1}{2}+1+2)=112$

$\Rightarrow 2^x.\frac{7}{2}=112$

$\Rightarrow 2^x=32$

$\Rightarrow 2^x=2^5$

$\Rightarrow x=5$

Vậy $x=5$

Answer 2

[⌛メ𝕹𝖊𝖕𝖆𝖑 ツ[𝕿𝖊𝖆𝖒 𝕹𝖊𝖕𝖆𝖑]]

\(2^{x-1}+2^x+2^{x+1}=112\)

\(2^x\cdot\frac{1}{2}+2^x+2^x\cdot2=112\)

\(2^x\cdot\left(\frac{1}{2}+1+2\right)=112\)

\(2^x\cdot\frac{7}{2}=112\)

\(2^x=32\)

\(\Rightarrow x=5\)