Answer :
[tex]200|2 \\ 100|2 \\ 50 \ |2 \\ 25 \ |5 \\ 5 \ \ |5 \\ 1 \\\\200=2^3*5^2 \\\\ 140|2 \\70 \ |2 \\ 35 \ |5 \\ 7 \ \ |7 \\1 \\\\ 140=2^2*5*7 \\\\ G.C.F(200;140)=2^2*5=20[/tex]
The factors of 200 are 1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, and 200 .
The factors of 140 are 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, and 140 .
The factors common to both are 1, 2, 4, 5, 10, and 20 .
The greatest one of those is 20 .
The factors of 140 are 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, and 140 .
The factors common to both are 1, 2, 4, 5, 10, and 20 .
The greatest one of those is 20 .