Question

Nốt bài này là xong r , giúp mk nốt nha

a) 3/7 - x = 1/4 - (-3/-5)

b)-21/-13x + 1/3= -2/-3

Answer 1

dễ vãi shit

Answer 2

a) \(\frac{3}{7}-x=\frac{1}{4}-\left(-\frac{3}{-5}\right)\)

\(\Rightarrow\frac{3}{7}-x=\frac{1}{4}-\frac{3}{5}\)

\(\Rightarrow\frac{3}{7}-x=\frac{-7}{20}\)

\(\Rightarrow x=\frac{3}{7}-\left(\frac{-7}{20}\right)=\frac{3}{7}+\frac{7}{20}\)

\(\Rightarrow x=\frac{109}{140}\)

b) \(\frac{-21}{-13x}+\frac{1}{3}=\frac{-2}{-3}\)

\(\Rightarrow\frac{21}{13x}+\frac{1}{3}=\frac{2}{3}\)

\(\Rightarrow\frac{21}{13x}=\frac{2}{3}-\frac{1}{3}=\frac{1}{3}\)

\(\Rightarrow13x=\frac{3.21}{1}=63\Rightarrow x=\frac{63}{13}\)

Answer 3

a.\(\frac{3}{7}-x=\frac{1}{4}-\left(\frac{-3}{-5}\right)\)

\(\frac{3}{7}-x=\frac{1}{4}-\frac{3}{5}\)

\(\frac{3}{7}-x=\frac{-7}{20}\)

\(x=\frac{109}{140}\)

Vậy\(x=\frac{109}{140}\)

b.\(\frac{-21}{-13}x+\frac{1}{3}=\frac{-2}{-3}\)

\(\frac{21}{13}x+\frac{1}{3}=\frac{2}{3}\)

\(\frac{21}{13}x=\frac{1}{3}\)

\(x=\frac{13}{63}\)

Vậy\(x=\frac{13}{63}\)