\(x+x\times\frac{1}{3}:\frac{2}{9}+x:\frac{2}{7}=252\)
\(x+x\times\frac{3}{2}+x\times\frac{7}{2}=252\)
\(x\times\left(1+\frac{3}{2}+\frac{7}{2}\right)=252\)
\(x\times6=252\)
\(x=252:6\)
\(x=42\)
X + X x \(\frac{1}{3}\)x\(\frac{9}{2}\)+ X x\(\frac{7}{2}\)= 252
X + X x \(\frac{3}{2}\)+ X x \(\frac{7}{2}\)= 252
X x (\(\frac{3}{2}\)+ \(\frac{7}{2}\)+1) = 252
X x (\(\frac{3}{2}\)+ \(\frac{7}{2}\)+ \(\frac{2}{2}\)) = 252
X x 6 = 252
X = 252 : 6
X= 42
Chúc bạn học tốt! ^^