Question

Tìm X, biết

a, X+ \(\dfrac{5}{6}=\dfrac{2}{5}-\dfrac{-2}{3}\)x

b,\(1\dfrac{2}{5}x+\dfrac{3}{7}=\dfrac{-4}{5}-\dfrac{1}{5}x\)

c,\(\dfrac{1}{3}-\dfrac{2}{3}\left(x-\dfrac{1}{2}\right)=1\)

Answer 1

a) \(x+\dfrac{5}{6}=\dfrac{2}{5}-\dfrac{-2}{3}x\)

\(x+\dfrac{5}{6}=\dfrac{2}{5}+\dfrac{2}{3}x\)

\(x-\dfrac{2}{3}x=\dfrac{2}{5}-\dfrac{5}{6}\)

\(\dfrac{1}{3}x=-\dfrac{13}{30}\)

\(x=-1,3\)

Answer 2

b) \(1\dfrac{2}{5}x+\dfrac{3}{7}=-\dfrac{4}{5}-\dfrac{1}{5}x\)

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

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

\(\dfrac{8}{5}x=-\dfrac{43}{35}\)

\(x=-\dfrac{43}{56}\)

Answer 3

c)\(\dfrac{1}{3}-\dfrac{2}{3}\left(x-\dfrac{1}{2}\right)=1\)

\(\dfrac{1}{3}-\dfrac{2}{3}x+\dfrac{1}{3}=1\)

\(-\dfrac{2}{3}x=1-\dfrac{1}{3}-\dfrac{1}{3}\)

\(-\dfrac{2}{3}x=\dfrac{1}{3}\)

\(x=-\dfrac{1}{2}\)

Answer 4

a)x+\(\dfrac{5}{6}\)=\(\dfrac{2}{3}-\dfrac{-2}{3}x\)

=>x+\(\dfrac{2}{3}x\)=\(\dfrac{2}{3}\)-\(\dfrac{5}{6}\)

=>\(\dfrac{5}{3}x\)=\(\dfrac{-1}{6}\)

=>\(x\)=\(\dfrac{-1}{10}\)

Vậy \(x=\dfrac{-1}{10}\)

b)1\(\dfrac{2}{5}x\)+\(\dfrac{3}{7}\)=\(\dfrac{-4}{5}-\dfrac{1}{5}x\)

=>\(\dfrac{7}{5}x\)+\(\dfrac{1}{5}x\)=\(\dfrac{-4}{5}-\dfrac{3}{7}\)

=>\(\dfrac{8}{5}x\)=\(\dfrac{-43}{35}\)

=>\(x\)=\(\dfrac{-43}{56}\)

KL:...

c)

=1-\(\dfrac{1}{3}\)

=>\(\dfrac{-2}{3}x\)+\(\dfrac{1}{3}\)=\(\dfrac{2}{3}\)

=>\(\dfrac{-2}{3}x\)=\(\dfrac{1}{3}\)

=>\(x\)=\(\dfrac{-1}{2}\)

KL: