Question

Answer 1

`[x-3]/13+[x-3]/14=[x-3]/15+[x-3]/16`

`=>[x-3]/13+[x-3]/14-[x-3]/15-[x-3]/16=0`

`=>(x-3)(1/13+1/14-1/15-1/16)=0`

  Mà `1/13+1/14-1/15-1/16 \ne 0`

 `=>x-3=0`

 `=>x=3`

Vậy `x=3`

Answer 2

\(\dfrac{x-3}{13}+\dfrac{x-3}{14}=\dfrac{x-3}{15}+\dfrac{x-3}{16}\)

`=> (x-3)/13 + (x-3)/14 - (x-3)/15 - (x-3)/16 =0`

`<=> (x-3)* (1/13 + 1/14 - 1/15 - 1/16) =0`

mà `(1/13 + 1/14 - 1/15 - 1/16)` khác `0`

`=> x-3 =0`

`=> x = 0+3=3`

 

Answer 3

`(x-3)/13 + (x-3)/14 = (x-3)/15 + (x-3)/16`

`<=> (x-3)/13 - (x-3)/14 - (x-3)/15 - (x-3)/16 = 0`

`=> (1/13 - 1/14 - 1/15 - 1/16).(x-3)=0`

ta thấy : 

`1/13 - 1/14 - 1/15 - 1/16` ko thể `=0`

Nên ta có :

`x-3=0`

`=> x = 0 + 3`

`=> x=3`

Answer 4

nó bị lỗi nên đăng lại 

Answer 5

\(\dfrac{x-3}{13}+\dfrac{x-3}{14}=\dfrac{x-3}{15}+\dfrac{x-3}{16}=\) 

\(\Rightarrow\) \(\dfrac{x-3}{13}+\dfrac{x-3}{14}-\dfrac{x-3}{15}-\dfrac{x-3}{16}=0\) 

\(\Rightarrow\left(x-3\right).\left(\dfrac{1}{13}+\dfrac{1}{14}-\dfrac{1}{15}-\dfrac{1}{16}\right)=0\) 

 mà \(\dfrac{1}{13}+\dfrac{1}{14}-\dfrac{1}{15}-\dfrac{1}{16}\) khác \(0\) 

 \(\rightarrow\) \(x-3=0\)

             \(x=3+0\) 

             \(x=3\)

 \(\Rightarrow\) Vậy \(x=3\)