tìm x, biết
1. -11/2x + 1= 1/3x - 1/4
2. 2x- 2/3 - 7x = 3/2 - 1
3. 3/2x - 2/5 = 1/3x - 1/4
4. 2/3 - 5/3x= 7/10x + 5/6
5. 2x -1/4 = 5/6 - 1/2x
6. 3x - 5/3 = x - 1/4
7. - 5/6 + 3x = 2/3 - 1/2x
8. 1/2 ( x + 2 ) - 4( x - 1/4 ) = 1/2x
9. 5/2( x - 3/5 ) - 1/10 = x-3
10. -4/3( x - 1/4 ) = 3/2( 2x - 1 )
Giúp mk với !!!
Bài 1:
- \(\dfrac{11}{2}x\) + 1 = \(\dfrac{1}{3}x-\dfrac{1}{4}\)
- \(\dfrac{11}{2}\)\(x\) - \(\dfrac{1}{3}\)\(x\) = - \(\dfrac{1}{4}\) - 1
-(\(\dfrac{33}{6}\) + \(\dfrac{2}{6}\))\(x\) = - \(\dfrac{5}{4}\)
- \(\dfrac{35}{6}\)\(x\) = - \(\dfrac{5}{4}\)
\(x=-\dfrac{5}{4}\) : (- \(\dfrac{35}{6}\))
\(x\) = \(\dfrac{3}{14}\)
Vậy \(x=\dfrac{3}{14}\)
Bài 2: 2\(x\) - \(\dfrac{2}{3}\) - 7\(x\) = \(\dfrac{3}{2}\) - 1
2\(x\) - 7\(x\) = \(\dfrac{3}{2}\) - 1 + \(\dfrac{2}{3}\)
- 5\(x\) = \(\dfrac{9}{6}\) - \(\dfrac{6}{6}\) + \(\dfrac{4}{6}\)
- 5\(x\) = \(\dfrac{7}{6}\)
\(x\) = \(\dfrac{7}{6}\) : (- 5)
\(x\) = - \(\dfrac{7}{30}\)
Vậy \(x=-\dfrac{7}{30}\)
Bài 3: \(\dfrac{3}{2}\)\(x\) - \(\dfrac{2}{5}\) = \(\dfrac{1}{3}x\) - \(\dfrac{1}{4}\)
\(\dfrac{3}{2}\)\(x\) - \(\dfrac{1}{3}x\) = \(-\dfrac{1}{4}\) + \(\dfrac{2}{5}\)
(\(\dfrac{9}{6}\) - \(\dfrac{2}{6}\))\(x\) = \(\dfrac{-5}{20}\) + \(\dfrac{8}{20}\)
\(\dfrac{7}{6}x\) = \(\dfrac{3}{20}\)
\(x\) = \(\dfrac{3}{20}\) : \(\dfrac{7}{6}\)
\(x\) = \(\dfrac{9}{70}\)
Vậy \(x=\dfrac{9}{70}\)
Bài 4: \(\dfrac{2}{3}\) - \(\dfrac{5}{3}\)\(x\) = \(\dfrac{7}{10}x\) + \(\dfrac{5}{6}\)
\(\dfrac{2}{3}\) - \(\dfrac{5}{6}\) = \(\dfrac{7}{10}\)\(x\) + \(\dfrac{5}{3}\)\(x\)
\(\dfrac{4}{6}\) - \(\dfrac{5}{6}\) = \(\dfrac{21}{30}\)\(x\) + \(\dfrac{50}{30}\)\(x\)
- \(\dfrac{1}{6}\) = \(\dfrac{71}{30}\)\(x\)
\(x=-\dfrac{1}{6}\) : \(\dfrac{71}{30}\)
\(x=-\)\(\dfrac{5}{71}\)
Vậy \(x=-\dfrac{5}{71}\)
Bài 5: 2\(x-\dfrac{1}{4}\) = \(\dfrac{5}{6}\) - \(\dfrac{1}{2}x\)
2\(x\) + \(\dfrac{1}{2}x\) = \(\dfrac{5}{6}\) + \(\dfrac{1}{4}\)
(\(\dfrac{4}{2}+\dfrac{1}{2}\))\(x\) = \(\dfrac{10}{12}\) + \(\dfrac{3}{12}\)
\(\dfrac{5}{2}x\) = \(\dfrac{13}{12}\)
\(x\) = \(\dfrac{13}{12}\) : \(\dfrac{5}{2}\)
\(x\) = \(\dfrac{13}{30}\)
Vậy \(x=\dfrac{13}{30}\)
Bài 6: 3\(x\) - \(\dfrac{5}{3}\) = \(x-\dfrac{1}{4}\)
3\(x\) - \(x\) = - \(\dfrac{1}{4}\) + \(\dfrac{5}{3}\)
2\(x\) = - \(\dfrac{3}{12}\) + \(\dfrac{20}{12}\)
2\(x\) = \(\dfrac{17}{12}\)
\(x=\dfrac{17}{12}:2\)
\(x=\dfrac{17}{24}\)
Vậy \(x=\dfrac{17}{24}\)
Bài 7: - \(\dfrac{5}{6}\) + 3\(x\) = \(\dfrac{2}{3}\) - \(\dfrac{1}{2}x\)
- \(\dfrac{5}{6}\) - \(\dfrac{2}{3}\) = - 3\(x\) - \(\dfrac{1}{2}\)\(x\)
- \(\dfrac{3}{2}\) = \(\dfrac{-7}{2}x\)
\(x=-\dfrac{3}{2}\) : \(\dfrac{-7}{2}\)
\(x=\dfrac{3}{7}\)
Vậy \(x=\dfrac{3}{7}\)
Bài 8:
\(\dfrac{1}{2}\).(\(x+2\)) - 4.(\(x-\dfrac{1}{4}\)) = \(\dfrac{1}{2}x\)
\(\dfrac{1}{2}x\) + 1 - 4\(x\) + 1 = \(\dfrac{1}{2}x\)
\(\dfrac{1}{2}x\) - 4\(x\) - \(\dfrac{1}{2}\)\(x\) = - 1 - 1
(\(\dfrac{1}{2}\) \(x\) - \(\dfrac{1}{2}\)\(x\)) - 4\(x\) = -2
0 - 4\(x\) = -2
-4\(x\) = -2
\(x\) = (-2) : (-4)
\(x=\dfrac{1}{2}\)
Vậy \(x=\dfrac{1}{2}\)
9; \(\dfrac{5}{2}\)(\(x-\dfrac{3}{5}\)) - \(\dfrac{1}{10}\) = \(x-3\)
\(\dfrac{5}{2}x\) - \(\dfrac{3}{2}\) - \(\dfrac{1}{10}\) = \(x-3\)
\(\dfrac{5}{2}\)\(x\) - \(x\) = \(\dfrac{3}{2}\) + \(\dfrac{1}{10}\) - 3
\(\dfrac{3}{2}x\) = \(\dfrac{8}{5}\) - 3
\(\dfrac{3}{2}\)\(x\) = -\(\dfrac{7}{5}\)
\(x=-\dfrac{7}{5}\):\(\dfrac{3}{2}\)
\(x=-\) \(\dfrac{14}{15}\)
Vậy \(x=-\dfrac{14}{15}\)
Bài 10:
- \(\dfrac{4}{3}\)(\(x-\dfrac{1}{4}\)) = \(\dfrac{3}{2}\)(2\(x-1\))
- \(\dfrac{4}{3}\)\(x\) + \(\dfrac{1}{3}\) = 3\(x\) - \(\dfrac{3}{2}\)
- \(\dfrac{4}{3}\)\(x\) - 3\(x\) = - \(\dfrac{3}{2}\) - \(\dfrac{1}{3}\)
\(\dfrac{-13}{3}\)\(x\) = - \(\dfrac{11}{6}\)
\(x\) = - \(\dfrac{11}{6}\) : - \(\dfrac{13}{3}\)
\(x\) = \(\dfrac{11}{26}\)
Vậy \(x=\dfrac{11}{26}\)