1b)\(\frac{7}{19}x\frac{8}{11}+\frac{3}{11}:\frac{19}{7}-\frac{2}{-19}=\frac{7}{19}x\frac{8}{11}+\frac{3}{11}x\frac{7}{19}+\frac{2}{19}=\left(\frac{8}{11}+\frac{3}{11}\right)\frac{7}{19}+\frac{2}{19}=\frac{7}{19}+\frac{2}{19}=\frac{9}{19}\)
c)\(4\left(\frac{4}{9}+\frac{7}{11}-\frac{4}{9}\right)=4\frac{7}{11}\)
từ rồi làm tiếp
2)
a)\(\frac{5}{6}-x=-\frac{5}{12}-\frac{1}{-4}=-\frac{5}{12}+\frac{1}{4}=-\frac{5}{12}+\frac{3}{12}=-\frac{1}{6}.\)
\(x=\frac{5}{6}--\frac{1}{6}=\frac{5}{6}+\frac{1}{6}=1\)
b)\(\frac{x-2}{-5}=\frac{6}{7}\)
\(\frac{\left(x-2\right)\left(-7\right)}{35}=\frac{30}{35}\)
\(\Rightarrow\left(x-2\right)\left(-7\right)=30\)
c)\(\frac{1}{2}x-\frac{3}{4}x=-\frac{5}{6}\)
\(\left(\frac{1}{2}-\frac{3}{4}\right)x=-\frac{5}{6}\)
\(-\frac{1}{4}x=-\frac{5}{6}\)
\(x=\frac{20}{6}=\frac{10}{3}\)
vậy \(x=\frac{10}{3}\)
