A/\(\frac{2}{3}+x=\frac{4}{7}\)
\(x=\frac{4}{7}-\frac{2}{3}\)
\(x=\frac{-2}{21}\)
B/\(\frac{7}{12}-\frac{5}{4}x=\frac{-2}{3}\)
\(\frac{5}{4}x=\frac{-2}{3}+\frac{7}{12}\)
\(\frac{5}{4}x=\frac{-1}{12}\)
\(x=\frac{-1}{12}:\frac{5}{4}\)
\(x=\frac{-1}{15}\)
C/\(\left|x+\frac{3}{4}\right|-5=-2\)
\(\left|x+\frac{3}{4}\right|=-2+\left(-5\right)\)
\(\Rightarrow\left|x+\frac{3}{4}\right|=-5 hoặc 5\)
\(\Rightarrow\)TH1:\(x+\frac{3}{4}=-5\)
\(x=-5-\frac{3}{4}\)
\(x=\frac{-23}{4}\)
\(\Rightarrow\)TH2:\(x+\frac{3}{4}=5\)
\(x=5-\frac{3}{4}\)
\(x=\frac{17}{4}\)