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 😡 = 4 4/9 +1
h (x+1/2). (2/3 – 2x)=0
i17/2 -|2x – 3/4| = -7/4
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 😡 = 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!!!