\(\frac{3}{4}+\frac{1}{4}:x=\frac{2}{5}\)
\(\Rightarrow\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\)
\(\frac{\Rightarrow1}{4}:x=-\frac{7}{20}\)
\(\Rightarrow x=\frac{1}{4}:\frac{-7}{20}\)
\(\Rightarrow x=-\frac{5}{7}\)
\(\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\)
\(\frac{1}{4}:x=\frac{-7}{20}\)
\(x=\frac{-28}{20}=\frac{-14}{10}=-1,4\)
Chúc bạn học tốt!!!
1/4:x=2/5-3/4
1/4:x=-7/20
x=1/4:-7/20
x=-5/7
\(\frac{3}{4}+\frac{1}{4}:x=\frac{2}{5}\)
\(=>\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\)
\(=>\frac{1}{4}:x=\frac{-7}{20}\)
\(=>x=\frac{1}{4}:\frac{-7}{20}\)
\(=>\frac{-5}{7}\)
\(\frac{3}{4}+\frac{1}{4}\div x=\frac{2}{5}\)
\(\frac{1}{4}\div x=\frac{2}{5}-\frac{3}{4}\)
\(\frac{1}{4}\div x=\frac{8}{20}-\frac{15}{20}\)
\(\frac{1}{4}\div x=-\frac{7}{20}\)
\(x=\frac{1}{4}\div\frac{-7}{20}\)
\(x=\frac{1}{4}×\frac{20}{-7}\)
\(x=\frac{20}{-28}=-\frac{5}{7}\)
Vậy,...
Cbht