Question

Câu 9. (2 điểm) Tìm số hữu tỉ $x$ trong các tỉ lệ thức sau:

a) $\dfrac x{-4} = \dfrac{-11}2$;

b) $\dfrac{15 - x}{x + 9} = \dfrac35$.

Answer 1

`x/(-4) = (-11)/2`

`=> 2x=-4.(-11)`

`=> 2x=44`

`=>x=44:2`

`=>x=22`

`---`

`(15-x)/(x+9) =3/5`

`=> (15-x).5=(x+9).3`

`=> 75-5x =3x+27`

`=> -5x -3x=27 -75`

`=> -8x=-48`

`=>x=-48:(-8)`

`=>x=6`

Answer 2

a) x−4=−112−4x​=2−11​

x=(−11).(−4)2x=2(−11).(−4)​

$x=22$.

b) 15−xx+9 =35x+915−x​ =53​

$(15-x).5=(x+9).3$

$75-5x=3x+27$

$8x=48$

$x=6$.

Answer 3

a)\(x=[\left(-4\right)\times\left(-11\right)]\div2=22\)

b)\(\dfrac{15-12}{\left(-4\right)+9}=\dfrac{3}{5}\)

Answer 4

15−��+9=35x+915-3​=53​=d

15−��+9=35

Answer 5

ưrw

Answer 6

  

Answer 7

111,23Ok

Answer 8

\(\dfrac{x}{-4}\) = \(\dfrac{-11}{2}\) => x.2 = (-4) . (-11) = (-4).(-11) : 2= 22

Answer 9

a) 22
b)3/5

Answer 10

a) x = 22

b) x = 6

Answer 11

$x/(-4)=(-11)/2$

$=>2x=-4.(-11)$

$=>2x=44$

$=>x=44:2$

$=>x=22$

$---$

$(15-x)/(x+9)=3/5$

$=>(15-x).5=(x+9).3$

$=>75-5x=3x+27$

$=>-5x-3x=27-75$

$=>-8x=-48$

$=>x=-48:(-8)$

$=>x=6$

Answer 12

a) x=22

b) x=6

Answer 13

a) x=(-11).(-4):2=22
b)\(\dfrac{x}{x}\)=\(\dfrac{15-3}{5+9}\)=\(\dfrac{12}{14}\)=\(\dfrac{6}{7}\)

Answer 14

x=-11.(-4)

Answer 15

a -22 

b 12

rrdrt

Answer 16

a,x x 2=-4x(-11)

x x 2 =44

x=44:2

x=22

Answer 17

như

Answer 18

a)x/-4=-11/2

--->x.2=-4.(-11)

      x.2=44

      x   =44:2

     x    = 22

 

 

Answer 19

22

Answer 20

(-11).(-4)=x.2

44=x.2

x=44:2

x=11

Vậy x=11

Answer 21

a)

x=22

b)

x=6

Answer 22

a, x=22

b, x=6

Answer 23

 

 

$x/(-4)=(-11)/2$

$=>2x=-4.(-11)$

$=>2x=44$

$=>x=44:2$

$=>x=22$

$---$

$(15-x)/(x+9)=3/5$

$=>(15-x).5=(x+9).3$

$=>75-5x=3x+27$

$=>-5x-3x=27-75$

$=>-8x=-48$

$=>x=-48:(-8)$

$=>x=6$

Answer 24

  

Answer 25

a, \(\dfrac{-11.\left(-4\right)}{2}\)= 22

b, 3.(x + 9) = 5.(15 - x)

 

Answer 26

Answer 27

Answer 28

a) x = -4.-11/2

x = 22

b) (15 - x ).5 = ( x + 9 ).3

75 - 5x = x3 + 27

8x = 48

x = 6

Answer 29

  

Answer 30