Question

[Lee Hoàng]

A, 11/4 - 2x = -1/2

B, |3/4 - 1/2x| + 1/3 = 5/6

Answer 1

[Lê Thị Thanh Huyền]

\(a)\frac{11}{4}-2x=\frac{-1}{2}\)

\(2x=\frac{11}{4}-\left(\frac{-1}{2}\right)\)

\(2x=\frac{11}{4}+\frac{1}{2}\)

\(2x=\frac{11}{4}+\frac{2}{4}\)

\(2x=\frac{13}{4}\)

\(x=\frac{13}{4}:2\)

\(x=\frac{13}{8}\)

\(b)\left|\frac{3}{4}-\frac{1}{2x}\right| +\frac{1}{3}=\frac{5}{6}\)

\(\left|\frac{3}{4}-\frac{1}{2x}\right|=\frac{5}{6}-\frac{1}{3}\)

\(\left|\frac{3}{4}-\frac{1}{2x}\right|=\frac{5}{6}-\frac{2}{6}\)

\(\left|\frac{3}{4}-\frac{1}{2x}\right|=\frac{3}{6}\)

\(TH1:\)

\(\frac{3}{4}-\frac{1}{2x}=\frac{3}{6}\)

\(\frac{1}{2x}=\frac{3}{4}-\frac{3}{6}\)

\(\frac{1}{2x}=\frac{18}{24}-\frac{12}{24}\)

\(\frac{1}{2x}=\frac{6}{24}\)

\(\frac{1}{2x}=\frac{1}{4}\)

\(\Rightarrow2x=4\)

\(x=4:2\)

\(x=2\)

\(TH2:\)

\(\frac{3}{4}-\frac{1}{2x}=\frac{-3}{6}\)

\(\frac{1}{2x}=\frac{3}{4}-\left(\frac{-3}{6}\right)\)

\(\frac{1}{2x}=\frac{3}{4}+\frac{3}{6}\)

\(\frac{1}{2x}=\frac{18}{24}+\frac{12}{24}\)

\(\frac{1}{2x}=\frac{30}{24}\)

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

\(\Rightarrow1:2x=5:4\)

\(1:2x=1,25\)

\(2x=1:1,25\)

\(2x=0,8\)

\(x=0,8:2\)

\(\)\(x=0,4\)