Question

tinh tong :

 \(\frac{2x}{2.5}+\frac{2x}{5.8}+\frac{2x}{8.11}+\frac{2x}{11.4}=\frac{1}{21}\)

Answer 1

\(2x.\left(\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}\right)=\frac{1}{21}\)

\(2x.\frac{1}{3}.\left(\frac{3}{2.5}+\frac{3}{5.8}+\frac{3}{8.11}+\frac{3}{11.14}\right)=\frac{1}{21}\)

\(2x.\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{14}\right)=\frac{1}{21}\)

\(2x.\frac{1}{3}.\frac{3}{7}=\frac{1}{21}\)

\(2x.\frac{1}{7}=\frac{1}{21}\)

\(2x=\frac{1}{3}\)

\(x=\frac{1}{6}\)

vậy \(x=\frac{1}{6}\)

Answer 2

cam on nhieu nhe ban