tìm x biết 1/2.x- 31 23/45 . 7/50 =18 22/45 .7/50 ( chú ý 31 23/45 là hợp số và 18 22/45 cũng thế)

$\dfrac{1}{2}.x – 31\dfrac{23}{45} . \dfrac{7}{50} = 18\dfrac{22}{45}.\dfrac{7}{50}$

$\to \dfrac{1}{2}.x =18\dfrac{22}{45}.\dfrac{7}{50} + 31\dfrac{23}{45}.\dfrac{7}{50}$

$\to \dfrac{1}{2}.x = \dfrac{7}{50}.\bigg(18\dfrac{22}{45}+31\dfrac{23}{45}\bigg)$

$\to \dfrac{1}{2}.x = \dfrac{7}{50}.50$

$\to \dfrac{x}{2} = 7$

$\to x= 7.2=14$

Vậy $x=14$