6.9 a, -1/3 x X =1 b, X x5/7 =-1/9 c, X : 4/7 =-5/7 d, -1/5 : X = -1/8

2 câu trả lời

a, -1/3 x X =1

⇒X=1: -1/3

⇒X=-3

Vậy X=-3

b, X x5/7 =-1/9

⇒X=-1/9:5/7

⇒X=-7/45

Vậy X=-7/45

c, X : 4/7 =-5/7

⇒X=4/7.-5/7

⇒X=-20/49

Vậy X=-20/49

d, -1/5 : X = -1/8

⇒X=-1/5:-1/8

⇒X=8/5

Vậy X=8/5

`a)-1/3xx x=1`

`x=1:(-1/3)`

`x=-3`

`b)x xx5/7=-1/9`

`xx=-1/9:5/7`

`xx=-7/45`

`c)x:4/7=-5/7`

`x=-5/7xx4/7`

`x=-20/49`

`d)-1/5:x=-1/8`

`x=-1/5:-1/8`

`x=-8/-5=8/5`