Chỉnh lại đi đề sai rồi.

Sửa đề.`18/117 × 12/113 + 12/113 × 8/117 + 26/117 × 101/113`

`= (18/117 + 8/117) × 12/113 + 26/117 × 101/113`

`= 26/117 × 12/113 + 26/117 × 101/113`

`= 26/117 × (12/113 + 101/113)`

`= 26/117 × 1`

`= 26/117`

\(\dfrac{19}{17}.\dfrac{5}{13}+\dfrac{5}{17}.\dfrac{7}{13}\)

\(=\dfrac{5}{17}.\dfrac{19}{13}+\dfrac{5}{17}.\dfrac{7}{13}\)

\(=\dfrac{5}{17}.\left(\dfrac{19}{13}+\dfrac{7}{13}\right)\)

\(=\dfrac{5}{17}.2\)

\(=\dfrac{10}{17}\)

\(\dfrac{4}{3}:\left(\dfrac{1}{2}+\dfrac{1}{3}\right)+\dfrac{4}{3}:\left(\dfrac{2}{3}+\dfrac{5}{2}\right)\)

\(=\dfrac{4}{3}:\dfrac{5}{6}+\dfrac{4}{3}:\dfrac{19}{6}\)

\(=\dfrac{4}{3}.\dfrac{6}{5}+\dfrac{4}{3}.\dfrac{6}{19}\)

\(=\dfrac{4}{1}.\dfrac{2}{5}+\dfrac{4}{1}.\dfrac{2}{19}\)

\(=\dfrac{4}{1}.\left(\dfrac{2}{5}+\dfrac{2}{19}\right)\)

\(=4.\dfrac{48}{95}\)

\(=\dfrac{192}{95}\)

\(\dfrac{5}{9}:\dfrac{11}{3}+\dfrac{4}{9}:\dfrac{11}{3}\)

\(=\dfrac{5}{9}.\dfrac{3}{11}+\dfrac{4}{9}.\dfrac{3}{11}\)

\(=\left(\dfrac{5}{9}+\dfrac{4}{9}\right).\dfrac{3}{11}\)

\(=1.\dfrac{3}{11}\)

\(3.x+\dfrac{3}{4}=2\)

\(3.x\)         \(=2-\dfrac{3}{4}\)

\(3.x\)        \(=\dfrac{5}{4}\)

   \(x\)        \(=\dfrac{5}{4}:3\)

  \(x\)         \(=\dfrac{5}{12}\)

\(\dfrac{7}{4}:2.x-1=\dfrac{7}{2}\)

\(\dfrac{7}{4}:2.x\)       \(=\dfrac{7}{2}+1\)

\(\dfrac{7}{4}:2.x\)       \(=\dfrac{9}{2}\)

\(\dfrac{7}{8}.x\)           \(=\dfrac{9}{2}\)

     \(x\)           \(=\dfrac{9}{2}:\dfrac{7}{8}\)

     \(x\)           \(=\dfrac{36}{7}\)

\(\dfrac{34}{27}:\dfrac{51}{18}+\dfrac{3}{4}:\dfrac{5}{8}\)

\(=\dfrac{34}{27}.\dfrac{18}{51}+\dfrac{3}{4}.\dfrac{8}{5}\)

\(=\dfrac{2}{3}.\dfrac{2}{3}+\dfrac{3}{1}.\dfrac{2}{5}\)

\(=\dfrac{4}{9}+\dfrac{6}{5}\)

\(=\dfrac{20}{45}+\dfrac{54}{45}\)

\(=\dfrac{74}{45}\)

`-4,5x - (0,25 - x) = -13/3`

`-4,5x - 0,25 +  x   = -13/3`

`-4,5x - 0,25 + x ×1  = -13/3`

`(-4,5 + 1) x - 0,25 = -13/3`

`-3,5x           - 0,25 = -13/3`

`-3,5x                       = -13/3 + 0,25`

`-3,5x                         = -49/12`

`     x                          = -49/12 ÷ -3,5`

`     x                         = 7/6`

`1/2x + 3/5x - 1/3x = -23/25`

`(1/2 + 3/5 - 1/3) x = -23/25`

`23/30.                    x = -23/25`

`                                 x = -23/25 ÷ 23/30`

`                                 x  = -6/5`

`-2/3x + 4x - 6/7 = 9/21`

`(-2/3 + 4)x - 6/7 = 9/21`

`(-2/3 + 4)x            = 9/21 + 6/7`

`(-2/3  + 4)x           = 3/7 + 6/7`

`(-2/3 + 4)x            = 9/7`

`10/3x                     = 9/7`

`          x                     = 9/7 ÷ 10/3`

`           x                     = 27/70`

`11/2 - x ÷ 1/2 = 1/4`

`             x ÷ 1/2 = 11/2 - 1/4`

`             x ÷ 1/2 = 21/4`

`             x             = 21/4 × 1/2`

`             x             = 21/8`

25/13 × 17/19 - 17/19 × 1/13 + 24/13 × 2/19

= (25/13 - 1/13) × 17/19 + 24/13 × 2/19

= 24/13 × 17/19 + 24/13 × 2/19

= 24/13 × (17/19 + 2/19)

= 24/13 × 1

= 24/13

Mình đọc chả biết rõ đề bài là như thế nào?