`\color{#7C71B2}{~ ~M}\color{#A193C6}{u}\color{#C8BBDC}{i}\color{#E1D8EB}{c}\color{#F0EEF7}{h}\color{#F0EEF7}{i}\color{#E1D8EB}{r}\color{#C8BBDC}{o}\color{#A193C6}{o}\color{#7C71B2}{o~ ~}`

Ta có: `36 = 2^2 . 3^2`

`24 = 2^3 .3`

`20 = 2^2 .5`

Suy ra `ƯCLN(36,24,30) = 2^2 = 4`

Hay `x\in ƯC(36,24,30) = Ư(4) = {1;2;4}`

Vậy...