Đáp án:
a) x= $\dfrac{7}{2}$
b) \(\left[ \begin{array}{l}x=\dfrac{-1}{2}\\x=\dfrac{3}{4}\end{array} \right.\)
c) x= $\dfrac{-2}{3}$
Giải thích các bước giải:
a) 2x - 3 = x+ $\dfrac{1}{2}$
2x - x= $\dfrac{1}{2}$ +3
x = $\dfrac{7}{2}$
b) $(x+ \dfrac{1}{2}$)$(x-\dfrac{3}{4}$) = 0
⇒ (x+ $\dfrac{1}{2}$)=0 ⇔x=$\dfrac{-1}{2}$
⇒ (x-$d\dfrac{3}{4}$)=0⇔x=$\dfrac{3}{4}$
c) $\dfrac{1}{3}$x + $\dfrac{2}{3}$(x+1)=0
$\dfrac{1}{3}$x + $\dfrac{2}{3}$x + $\dfrac{2}{3}$.1=0
x($\dfrac{1}{3}$+$\dfrac{2}{3}$) + $\dfrac{2}{3}$=0
x($\dfrac{3}{3}$ + $\dfrac{2}{3}$ = 0
x + $\dfrac{2}{3}=0
⇒x=0-$\dfrac{2}{3}$ =0
⇒x=$\dfrac{-2}{3}
