\(x+x\times\frac{1}{4}\div\frac{2}{7}+x\div\frac{2}{9}=255\)
\(\Rightarrow x+x\times\frac{1}{4}\times\frac{7}{2}+x\times\frac{9}{2}=255\)
\(\Rightarrow x+x\times\frac{7}{8}+x\times\frac{9}{2}=255\)
\(\Rightarrow x.\left(1+\frac{7}{8}+\frac{9}{2}\right)=255\)
\(\Rightarrow x\cdot\frac{51}{8}=255\)
\(\Rightarrow x=255\div\frac{51}{8}\)
\(\Rightarrow x=255\times\frac{8}{51}\)
\(\Rightarrow x=40\)
Vậy x = 40