Question

Answer 1

g: \(x-4=\dfrac{-14}{35}:\dfrac{5}{7}=\dfrac{-2}{5}\cdot\dfrac{7}{5}=\dfrac{-14}{25}\)

nên \(x=-\dfrac{14}{25}+4=-\dfrac{14}{25}+\dfrac{100}{25}=\dfrac{86}{25}\)

h: \(x\cdot\dfrac{-3}{7}=\dfrac{3}{56}\cdot\dfrac{28}{9}=\dfrac{3}{9}\cdot\dfrac{28}{56}=\dfrac{1}{6}\)

nên \(x=\dfrac{1}{6}:\dfrac{-3}{7}=\dfrac{-7}{18}\)

i: \(x\cdot\dfrac{1}{4}-\dfrac{7}{5}=\dfrac{-5}{8}:\dfrac{15}{4}=\dfrac{-5}{8}\cdot\dfrac{4}{15}=\dfrac{-1}{6}\)

\(\Leftrightarrow x\cdot\dfrac{1}{4}=\dfrac{-1}{6}+\dfrac{7}{5}=\dfrac{-5}{30}+\dfrac{42}{30}=\dfrac{37}{30}\)

hay \(x=\dfrac{37}{30}:\dfrac{1}{4}=\dfrac{37}{30}\cdot4=\dfrac{74}{15}\)