Question

Tìm x : \(\left|\frac{3}{4}+\frac{1}{4}:x\right|=\frac{2}{5}\)

b) \(\frac{2}{3}x-1\frac{2}{5}=\frac{1}{2}x+0,8\)

c) \(\left|2x-1\right|-x=1\)

Answer 1

Answer 2

Answer 3

a)\(\left|\frac{3}{4}+\frac{1}{4}:x\right|=\frac{2}{5}\)

TH1:\(\frac{3}{4}+\frac{1}{4}:x=\frac{2}{5}\) TH2:\(\frac{3}{4}+\frac{1}{4}:x=\frac{-2}{5}\)

\(\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\) \(\frac{1}{4}:x=\frac{-2}{5}-\frac{3}{4}\)

\(\frac{1}{4}:x=\frac{-7}{20}\) \(\frac{1}{4}:x=\frac{-23}{20}\)

\(x=\frac{1}{4}.\frac{-7}{20}\) \(x=\frac{1}{4}.\frac{-20}{23}\)

\(x=\frac{-5}{7}\) \(x=\frac{-5}{23}\)

Vậy x=\(\frac{-5}{7}\) hoặc x=\(\frac{-5}{23}\)

b)\(\frac{2}{3}x-1\frac{2}{5}=\frac{1}{2}x+0,8\)

\(\frac{2}{3}-\frac{7}{5}=\frac{1}{2}x+0,8\)

\(\frac{2}{3}x-\frac{1}{2}x=0,8+\frac{7}{5}\)

\(\frac{1}{6}x=\frac{11}{5}\)

\(x=\frac{11}{5}:\frac{1}{6}\)

\(x=\frac{66}{5}\)

c)\(\left|2x-1\right|-x=1\)

\(\Rightarrow\left|2x-1\right|=1+x\)

TH1:\(2x-1=1+x\) TH2:\(2x-1=-1+x\)

\(\Rightarrow2x-1=1+x\) \(\Rightarrow2x-1=-1+x\)

\(x\)\(=2\) \(x=0\)

Vậy x=2 hoặc x=0

Nhớ tick cho mình nhé!