The GCF is 5.
Take your pick; 10 and 20, 10 and 30, 10 and 40, 10 and 50, 10 and 60, 10 and 70, 10 and 80, 10 and 90, 20 and 30, 20 and 50, 20 and 70, 20 and 90, 30 and 40, 30 and 50, 30 and 70, 30 and 80, 40 and 50, 40 and 70, 40 and 90, 50 and 60, 50 and 70, 50 and 80 50 and 90, 60 and 70, 70 and 80, 70 and 90, 80 and 90.
The GCF is 5.
thw greastest common factor of 10 50 and 70 is 10
The GCF is 10.
The GCF of 30, 50, and 70 is 10.
10
If that's 30, 50 and 70, the GCF is 10.
The GCF of 50 and 70 is 10.
The GCF is 5.
Take your pick; 10 and 20, 10 and 30, 10 and 40, 10 and 50, 10 and 60, 10 and 70, 10 and 80, 10 and 90, 20 and 30, 20 and 50, 20 and 70, 20 and 90, 30 and 40, 30 and 50, 30 and 70, 30 and 80, 40 and 50, 40 and 70, 40 and 90, 50 and 60, 50 and 70, 50 and 80 50 and 90, 60 and 70, 70 and 80, 70 and 90, 80 and 90.
The GCF is 5.
10 and 210, respectively.
GCF(30, 50) = 10.
The GCF is 5.
The GCF is 10.
The GCF of 50 and 30 is 10. (I believe you meant to ask "What ?" instead of "Why ?".)