a.2/3x+1/4=7/12 b.x/7 =-6/21 c5 4/7:x=13 f.(2 4/5 x-50) : 2/3 = 51 g. 4 2/3 :x = 4 4/9 +1 h (x+1/2). (2/3 – 2x)=0 i17/2 -|2x – 3/4| = -7/4

Đáp án:

$a.2/3x+1/4=7/12$

$⇔ 2/3 x = 7/12 – 1/4$

$⇔ 2/3 x = 1/3$

$⇔ x = 1/3 : 2/3$

$⇔ x = 0,5$

$b.x/7 =-6/21$

$⇔ x = -6/21 . 7$

$⇔ x = -2$

$c. 5$$\dfrac{4}{7}$ $:x=13$

$⇔ 39/7 : x = 13$

$⇔ x = 39/7 : 13$

$⇔ x = 3/7$

$f.(2$$\dfrac{4}{5}$ $x-50) : 2/3 = 51$

$⇔ 2,8 x – 50 = 51. 2/3$

$⇔ 2,8 x – 50 = 34$

$⇔ 2,8 x = 84$

$⇔ x = 84: 2,8$

$⇔ x = 30$

$g. 4$$\dfrac{2}{3}$ $ 😡 = 4$$\dfrac{4}{9}$  $+1$

$⇔14/3 : x = 40/9 + 1 $

$⇔ 14/3 : x = 49/9$

$⇔ x = 14/3 : 49/9$

$⇔ x = 6/7$

$h (x+1/2). (2/3 – 2x)=0$

$⇔ x+1/2 = 0$ hoặc $2/3 – 2x=0$

$⇔ x= -1/2$ hoặc $2x=2/3$

$⇔ x=-1/2$ hoặc$ x=1/3$

$i 17/2 -|2x – 3/4| = -7/4$

$⇔ |2x-3/4| = 17/2 – (-7/4)$

$⇔ |2x-3/4| = 10,25$

$⇔ 2x-3/4 = 10,25$ hoặc $2x-3/4 = -10,25$

$⇔ 2x = 11$ hoặc $2x = -9,5$

$⇔ x = 11/2$ hoặc $x = -4,75$

BẠN THAM KHẢO NHA!!!

 

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