Đáp án: $x=14$
Giải thích các bước giải:
$\dfrac{1}{2}.x - 31\dfrac{23}{45} . \dfrac{7}{50} = 18\dfrac{22}{45}.\dfrac{7}{50}$
$\to \dfrac{1}{2}.x =18\dfrac{22}{45}.\dfrac{7}{50} + 31\dfrac{23}{45}.\dfrac{7}{50}$
$\to \dfrac{1}{2}.x = \dfrac{7}{50}.\bigg(18\dfrac{22}{45}+31\dfrac{23}{45}\bigg)$
$\to \dfrac{1}{2}.x = \dfrac{7}{50}.50$
$\to \dfrac{x}{2} = 7$
$\to x= 7.2=14$
Vậy $x=14$