`13) - x/24 = 10/(-y) = z/9 = 5/1`

`-x/24 = 5/1 ⇔ -x = 24 . 5 ⇔ x = -120`

`10/(-y) = 5/1 ⇔ -y = 10/5 ⇔ y = -2`

`z/9 = 5/1 ⇔ z = 5 . 9 =45`

`14) 34/x = -y/6 = z/5 = 17/1` (ĐK : $x\neq0$ )

`34/x = 17/1 ⇔ x = 34/17 = 2` (TM)

`-y/6 = 17/1 ⇔ - y = 17 . 6 ⇔ y =-102`

`z/5 = 17/1 ⇔ z = 17.5 = 85`

` 15) -32/x = 16/y = - z/10 = 1/5` ĐK : $x;y\neq0$ )

` -32/x = 1/5 ⇔ x = -32. 5 =-160` (TM)

` 16/y = 1/5 ⇔ y = 16.5 = 80` (TM)

`-z/10 = 1/5 ⇔ -z = 10/5 ⇔ z = -2`