\(x+x\times\frac{1}{4}:\frac{2}{7}+x:\frac{2}{9}=255\)
\(x+x\times\frac{1}{4}\times\frac{7}{2}+x\times\frac{9}{2}=255\)
\(x\times\left(1+\frac{1}{4}\times\frac{7}{2}+\frac{9}{2}\right)=255\)
\(x\times\frac{51}{38}=255\)
\(x=255:\frac{51}{38}\)
\(x=190\)
\(x+x.\frac{1}{4}:\frac{2}{7}+x:\frac{2}{9}=255\)
\(\Rightarrow x+x.\frac{1}{4}.\frac{7}{2}+x.\frac{9}{2}=255\)
\(\Rightarrow x+x.\frac{7}{8}+x.\frac{9}{2}=255\)
\(\Rightarrow x.\left(1+\frac{7}{8}+\frac{9}{2}\right)=255\)
\(\Rightarrow x.\frac{51}{8}=255\)
\(\Rightarrow x=255:\frac{51}{8}\)
\(\Rightarrow x=40\)
Vậy x = 40
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