Question

Tìm x biết :

a) x + \(\frac{1}{3}\) = \(\frac{3}{4}\)

b) x - \(\frac{2}{5}\) = \(\frac{5}{7}\)

c) -x -\(\frac{2}{3}\) = -\(\frac{6}{7}\)

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

Các bạn giải giúp cho mình với ! 

Answer 1

a) \(x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}\)

b) \(x=\frac{5}{7}+\frac{2}{5}=\frac{39}{35}\)

c) \(-x=-\frac{6}{7}+\frac{2}{3}=-\frac{4}{21}\Leftrightarrow x=\frac{4}{21}\)

d) \(x=\frac{4}{7}-\frac{1}{3}=\frac{5}{21}\)

Answer 2

a/ \(x+\frac{1}{3}=\frac{3}{4}\)

\(x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}\)

b/\(x-\frac{2}{5}=\frac{5}{7}\)

\(x=\frac{5}{7}+\frac{2}{5}=\frac{39}{35}\)

c/\(-x-\frac{2}{3}=-\frac{6}{7}\)

\(-x=-\frac{6}{7}+\frac{2}{3}=-\frac{4}{21}\)

\(\rightarrow x=\frac{4}{21}\)

d/ \(-\frac{4}{7}-x=\frac{1}{3}\)

\(x=\left(-\frac{4}{7}\right)-\frac{1}{3}=-\frac{19}{21}\)

Answer 3

a) x = 3/4 - 1/3 = 5/12

b) x = 5/7 + 2/5 = 39/35

c) -x = -6/7 + 2/3 = -4/21

=> x = 4/21

d) x = 4/7 -1/3 = 5/21

Answer 4

a) \(x+\frac{1}{3}=\frac{3}{4}\)

=> \(x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}\)

b) \(x-\frac{2}{5}=\frac{5}{7}\)

=> \(x=\frac{5}{7}+\frac{2}{5}\) = \(\frac{39}{35}\)

c) - x - \(\frac{2}{3}=-\frac{6}{7}\)

=> - x =  \(-\frac{6}{7}+\frac{2}{3}=-\frac{4}{21}\)

=> x = \(\frac{4}{21}\)

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

=> \(x=\frac{4}{7}-\frac{1}{3}\) = \(\frac{5}{21}\)

 

Answer 5

Nhầm câu d Sorry

Answer 6

a, \(x+\frac{1}{3}=\frac{3}{4}\)

\(\Leftrightarrow x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}.\)

vậy \(x=\frac{5}{12}\)

b, \(x-\frac{2}{5}=\frac{5}{7}\)

\(\Leftrightarrow x=\frac{5}{7}+\frac{2}{5}=\frac{39}{35}\)

vậy \(x=\frac{39}{35}\)

c, \(-x-\frac{2}{3}=\frac{-6}{7}\)

\(\Leftrightarrow-x=\frac{-6}{7}+\frac{2}{3}=\frac{-4}{21}\)

\(\Leftrightarrow x=\frac{4}{21}\)

vậy \(x=\frac{4}{21}\)

d, \(\frac{4}{7}-x=\frac{1}{3}\)

\(\Leftrightarrow-x=\frac{1}{3}-\frac{4}{7}=\frac{-5}{21}\)

\(\Leftrightarrow x=\frac{5}{21}\)

vậy \(x=\frac{5}{21}\)