1/2x-3/4=-1 1/4 3/2-1/2:x=5/4 1/3+2/3.x+-7

Đáp án:

  $\text{$\dfrac{1}{2}$x - $\dfrac{3}{4}$ = $\dfrac{-11}{4}$}$

$\text{<=> $\dfrac{1}{2}$x = $\dfrac{-11}{4}$ + $\dfrac{3}{4}$ }$

$\text{<=> $\dfrac{1}{2}$x= -2 }$

$\text{<=> x = -2 : $\dfrac{1}{2}$ }$

$\text{<=> x =-4 }$

$\text{Vậy x = -4}$

$\text{ $\dfrac{3}{2}$ - $\dfrac{1}{2}$ : x = $\dfrac{5}{4}$  }$

$\text{<=> $\dfrac{-1}{2}$ : x = $\dfrac{5}{4}$ - $\dfrac{3}{2}$ }$

$\text{<=> $\dfrac{-1}{2}$ : x =$\dfrac{-1}{4}$ }$

$\text{<=> x = $\dfrac{-1}{2}$ : $\dfrac{-1}{4}$ }$

$\text{<=>x = 2 }$

$\text{ Vậy x= 2 }$

$\text{$\dfrac{1}{3}$ + $\dfrac{2}{3}$x -7 =0}$

$\text{<=> $\dfrac{2}{3}$x = 7 - $\dfrac{1}{3}$ }$

$\text{<=> $\dfrac{2}{3}$x = $\dfrac{20}{3}$ }$

$\text{<=> x =  $\dfrac{20}{3}$ : $\dfrac{2}{3}$ }$

$\text{<=> x = 10 }$

$\text{Vậy x= 10  }$