\(3y-x=6\) => \(x=3y-6\)
Thay \(x=3y-6\) vào biểu thức A. Ta có:
\(A=\left(\frac{3y-6}{y-2}\right)+\left(\frac{2\left(3y-6\right)-3y}{3y-6-6}\right)=\left(\frac{3\left(y-2\right)}{y-2}\right)+\left(\frac{6y-12-3y}{3y-12}\right)\)
\(A=\left(\frac{3\left(y-2\right)}{y-2}\right)+\left(\frac{3y-12}{3y-12}\right)=3+1=4\)
bn \(2x-\frac{3y}{x}-6\)
hay là \(\frac{2x-3y}{x-6}\)