\(\left(x-5\right)^2=\left(1-3x\right)^2\)

=>  \(x-5=1-3x\)

=>  \(4x=6\)

=>   \(x=\frac{6}{4}\)

=>  \(x=\frac{3}{2}\)

8.

\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2^n\)

\(\Rightarrow\frac{4^5.4}{3^5.3}.\frac{6^5.6}{2^5.2}=2^n\)\(\Rightarrow\frac{4^6}{3^6}.\frac{6^6}{2^6}=2^n\)

\(\Rightarrow\frac{\left(2^2\right)^6.\left(2.3\right)^6}{3^6.2^6}=2^n\)\(\Rightarrow\frac{2^{12}.3^6.2^6}{3^6.2^6}=2^n\)

\(\Rightarrow2^{12}=2^n\)=> n = 12

9.

\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.....\frac{31}{64}=2^n\)

\(\Rightarrow\frac{1}{2.2}.\frac{2}{2.3}.\frac{3}{2.4}.....\frac{31}{2.32}=2^n\)

\(\Rightarrow\frac{1}{2^{16}}.\left(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.....\frac{31}{32}\right)=2^n\)

\(\Rightarrow2^{-16}.\left(\frac{1.2.3.....31}{2.3.4.....32}\right)=2^n\)

\(\Rightarrow2^{-16}.\frac{1}{32}=2^n\)

\(\Rightarrow2^{-16}.\frac{1}{2^5}=2^n\)

\(\Rightarrow2^{-16}.2^{-5}=2^n\)

\(\Rightarrow2^{-21}=2^n\)

=> n = -21

từ 1/10 rùi mà anh

mik cx muốn giúp lắm nhưng mik học c3 rồi ko nhớ cách cấp 2 :)) 

1 chia 2 bằng bao nhiêu các bạn chỉ giúp mình với

\(\left(x+\frac{2}{3}\right)^{2012}+\left|y-\frac{1}{4}\right|^{2000}+\left(x-y-z\right)^{2014}=0\)

\(\Leftrightarrow\hept{\begin{cases}x+\frac{2}{3}=0\\y-\frac{1}{4}=0\\x-y-z=0\end{cases}}\)

\(\Leftrightarrow\hept{\begin{cases}x=-\frac{2}{3}\\y=\frac{1}{4}\\z=-\frac{11}{12}\end{cases}}\).

Bài 1 :

Để \(A=\frac{x+15}{x-2}\)là số nguyên thì :

x + 15 ⋮ x - 2

=> ( x - 2 ) + 17 ⋮ x - 2

Mà x - 2 ⋮ x - 2 ∀ x ∈ Z

=> 17 ⋮ x - 2

=> x - 2 ∈ { -17 ; -1 ; 1 ; 17 }

=> x ∈ { -15 ; 1 ; 3 ; 19 }

Để \(B=\frac{3x+4}{x-3}\)nhận giá trị nguyên thì :

3x + 4 ⋮ x - 3

=> 3( x - 3 ) + 13 ⋮ x - 3

Mà 3( x - 3 ) ⋮ x - 3 ∀ x ∈ Z

=> 13 ⋮ x - 3

=> x - 3 ∈ { -13 ; -1 ; 1 ; 13 }

=> x ∈ { -10 ; 2 ; 4 ; 16 }