Đáp án:
`↓↓↓`
Giải thích các bước giải:
`a) x/(-3) = 4/y`
`-> xy = -3 . 4`
`-> xy = -12`
`-> x,y ∈ Ư (-12) = {±1; ±2; ±3; ±4; ±6; ±2}`
`-> x ∈ Ư (-12) = {±1; ±2; ±3; ±4; ±6; ±2}`
`-> y ∈ Ư (-12) = {±1; ±2; ±3; ±4; ±6; ±2}`
Vậy ..
`b) 2/x = y/9`
`-> 2 . 9 = xy`
`-> xy = 18`
`-> x,y ∈ Ư (18) = {±1; ±2; ±3; ±6; ±9; ±18}`
`-> x ∈ Ư (18) = {±1; ±2; ±3; ±6; ±9; ±18}`
`-> y ∈ Ư (18) = {±1; ±2; ±3; ±6; ±9; ±18}`
Vậy ..
`c) x/y = 2/5`
`-> x . 5 = y . 2`
`-> x . y = 5 . 2`
`-> xy = 10`
`-> x,y ∈ Ư (10) = {±1; ±2; ±5; ±10}`
`-> x ∈ Ư (10) = {±1; ±2; ±5; ±10}`
`-> y ∈ Ư (10) = {±1; ±2; ±5; ±10}`
Vậy ..
`d) x/3 = y/7`
`-> x . 7 = 3 . y`
`-> x . y = 3 . 7`
`-> xy = 21`
`-> x,y ∈ Ư (21) = {±1; ±3; ±7; ±21}`
`-> x ∈ Ư (21) = {±1; ±3; ±7; ±21}`
`-> y ∈ Ư (21) = {±1; ±3; ±7; ±21}`
Vậy ..