Question

MMC E MDC
m.m.c. 9,15,20
m.d.c 30,75
m.m.c. 24,36,72
m.d.c. 20,60,80

Answer 1

a)
m.m.c. 9,15,20

9,15,20: 2
9,15,10: 2
9,15,5: 3
3,5,5: 3
1,5,5: 5
--------------------
1,1,1   = 2².3².5 = 4.9.5 = 36.5 = 180

R.: mmc (9,15,20) = 180

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b)Máximo Divisor Comum: divide os dois números ao mesmo tempo.

m.d.c 30,75

30,75: 2
15,75: 3
5,25: 5
1,5: 5
-----------
1,1  =   3.5 = 15

R.: mdc (30,75) = 15 

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c)

m.m.c. 24,36,72

R.: mmc (24,36,72) = 72

24,36,72: 2
12,18,36: 2
6,9,18: 2
3,9,9: 3
1,3,3: 3
-------------------
1,1,1  = 2³.3² = 8.9 = 72

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d)

m.d.c. 20,60,80

20,60,80: 2
10,30,40: 2
5,15,20: 2
5,15,10: 2
5,15,5: 3
5,5,5: 5
-----------------------
1,1,1    =  2.2.5 = 4.5 = 20

R.: mdc (20,60,80) = 20