=>-x-5/6=7/12-4/12=3/12=1/4
=>-x=1/4+5/6=13/12
hay x=-13/12
\(\Rightarrow-\dfrac{5}{6}-x=\dfrac{1}{4}\)
\(\Rightarrow x=-\dfrac{5}{6}-\dfrac{1}{4}\)
\(\Rightarrow x=-\dfrac{13}{12}\)
C)\(\dfrac{-5}{6}-x=\dfrac{7}{12}+\dfrac{-1}{3}\)
\(\dfrac{-5}{6}-x=\dfrac{7}{12}+\dfrac{-4}{12}\)
\(\dfrac{-5}{6}-x=\dfrac{1}{4}\)
\(x=\dfrac{-5}{6}-\dfrac{1}{4}\)
\(x=\dfrac{-20}{24}-\dfrac{6}{24}\)
\(x=\dfrac{14}{24}=\dfrac{7}{12}\)
-5/6 - x = 7/12 + -1/3
-5/6 - x = 1/4
x = -5/6 - 1/4
x = -13/12
vậy x = ....
