Question

Tìm x biết:

\(\dfrac{3}{4}.x+\dfrac{1}{5}=\dfrac{1}{6}\)

b)(\(4\dfrac{1}{2}-\dfrac{2}{5}x\)):\(\dfrac{7}{4}=\dfrac{11}{14}\)

Answer 1

a, \(\dfrac{3}{4}.x+\dfrac{1}{5}=\dfrac{1}{6}\)

\(\dfrac{3}{4}.x=\dfrac{1}{6}-\dfrac{1}{5}\)

\(\dfrac{3}{4}.x=\dfrac{-1}{30}\)

\(x=\dfrac{-1}{30}:\dfrac{3}{4}\)

\(x=\dfrac{-2}{45}\)

b, \(\left(4\dfrac{1}{2}-\dfrac{2}{5}x\right):\dfrac{7}{4}=\dfrac{11}{14}\)

\(\left(4\dfrac{1}{2}-\dfrac{2}{5}x\right)=\dfrac{11}{14}.\dfrac{7}{4}\)

\(4\dfrac{1}{2}-\dfrac{2}{5}x=\dfrac{11}{8}\)

\(\dfrac{2}{5}x=4\dfrac{1}{2}-\dfrac{11}{8}\)

\(\dfrac{2}{5}x=\dfrac{9}{2}-\dfrac{11}{8}\)

\(\dfrac{2}{5}x=\dfrac{25}{8}\)

\(x=\dfrac{25}{8}:\dfrac{2}{5}\)

\(x=\dfrac{125}{16}\)

Answer 2

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