2.x/ 3- x/ 4= 5/ 6
⇒ 4. ( 2. x) / 12 - 3.x/ 12= 10/ 12
⇔ 8.x - 3. x/ 12= 10/ 12
⇒ 8. x- 3. x= 10
⇔ ( 8- 3). x= 10
⇔ 5. x= 10
⇔ x= 10: 5
⇔ x= 2
Vậy x= 2
b, 1,5 + $1$ $\dfrac{1}{3}$ x $x$ = $2$ $\dfrac{1}{4}$
⇔ 1, 5+ $\dfrac{4}{3}$ x $x$ =$\dfrac{9}{4}$
⇒ $\dfrac{4}{3}$ x $x$ = $\dfrac{9}{4}$ $-$ $1, 5$
⇔ $\dfrac{4}{3}$ x $x$= $\dfrac{9}{4}$ $-$ $\dfrac{6}{4}$
⇔$\dfrac{4}{3}$ x $x$ $=$ $\dfrac{3}{4}$
⇔ $x$ $=$ $\dfrac{3}{4}$ $:$ $\dfrac{4}{3}$
⇔ $x$ $=$ $\dfrac{9}{16}$
Vậy $x$ $=$ $\dfrac{9}{16}$
Chúc học tốt!
