tìm X,Y c) 4/5 = 68/X d) X/17 = 60/204

`4/5 = 68/x `

`=> 4 xx x = 68 xx 5`

`=> x = 340 : 4 `

`=> x= 85`

Vậy `x = 85`

`---`

`x/17 = 60/204`

`=> x xx 204 = 60 xx 17`

`=> x = 1020 : 204`

`=> x = 5`

Vậy `x= 5`