Question

Tìm các số nguyên biết :

a) 3/x + 1/3 = y/3 

b) x/6 - 1/y = 1/2 

 

Answer 1

\(A)\) \(\dfrac{\text{3}}{\text{x }}=\dfrac{\text{1}}{\text{3}}=\dfrac{\text{y}}{\text{3}}\)

\(\text{⇒}\dfrac{\text{3}}{\text{x}}=\dfrac{y}{3}-\dfrac{1}{\text{3}}\)

\(=>\dfrac{\text{3}}{\text{x }}=\dfrac{\text{y − 1}}{\text{3}}\)

\(⇒ x y − x = 9\)

\(⇒ x ( y − 1 ) = 9\)

\(-------\)

\(B)\) \(\dfrac{\text{x}}{\text{6}}\) \(-\) \(\dfrac{\text{1}}{\text{y }}\) \(=\) \(\dfrac{\text{1}}{\text{2}}\)

\(=>\) \(\dfrac{\text{1}}{\text{y}}\) \(=\) \(\dfrac{\text{x}}{\text{6}}\) \(-\) \(\dfrac{\text{1}}{\text{2}}\)

\(=>\) \(\dfrac{\text{1}}{\text{y}}=\dfrac{\text{x}}{\text{6}}-\dfrac{3}{6}\)

\(=>\dfrac{1}{y}=\dfrac{x-3}{6}\)

\(⇒ y . ( x − 3 ) = 6\)