Question

3y+x=x:y=5(x+y)

Tìm x,y

Answer 1

3y + x = x : y = 5 . ( x + y )

Ta có : 

3y + x = 5 . ( x + y )

3y + x = 5x + 5y

3y - 5y = 5x - x

-2y = 4x

\(\frac{x}{y}=\frac{-2}{4}=\frac{-1}{2}\)

\(\Rightarrow5.\left(x+y\right)=\frac{-1}{2}\)

\(\Rightarrow x+y=\frac{-1}{10}\)

Mà 3y + x = \(\frac{-1}{2}\)

2y + ( y + x ) = \(\frac{-1}{2}\)

2y + \(\frac{-1}{10}=\frac{-1}{2}\)

\(2y=\frac{-1}{2}-\frac{-1}{10}\)

\(2y=\frac{-2}{5}\)

\(y=\frac{-2}{5}:2=\frac{-1}{5}\)

\(\Rightarrow x=\frac{-1}{10}-\frac{-1}{5}=\frac{1}{10}\)

Vậy x = \(\frac{1}{10}\); y = \(\frac{-1}{5}\)