Explicação passo-a-passo:
a)
[tex]\begin{array}{r|l} 20,30,45&2\\ 10,15,45&2\\ 5,15,45&3\\ 5,5,15&3\\ 5,5,5&5 \\ 1,1,1 \\ &\boxed{\red{\mathsf{mdc \: 20,30,45) \: = 5}}} \end{array}[/tex]
b)
[tex]\begin{array}{r|l} 12,15,30&2\\ 6,15,15&2\\ 3,15,15&3\\ 1,5,5&5\\ 1,1,1 \\ &\boxed{\red{\mathsf{mdc \: (12,15,30) \: = 3}}}\end{array}[/tex]
c)
[tex]\begin{array}{r|l} 100,150&2\\ 50,75&2\\ 25,75&3\\ 25,25&25\\ 1,1 \\ &\boxed{\red{\mathsf{mdc \: (100,150) \: = 50}}} \end{array}[/tex]
Att: Armando
