I think you might mean "GCF".....if so...let's break each number down into its prime factors......so we have...
72 = 8 x 9 = 2^3 x 3^2
120 = 10 x 12 = 5 x 2 x 4 x 3 = 5 x 2 x 2 x 2 x 3 = 2^3 x 3 x 5
Now, we just select each different factor having the highest power...so we have
2^3 x 3^2 x 5 = 8 x 9 x 5 = 360
And that's the GCF
I think you might mean "GCF".....if so...let's break each number down into its prime factors......so we have...
72 = 8 x 9 = 2^3 x 3^2
120 = 10 x 12 = 5 x 2 x 4 x 3 = 5 x 2 x 2 x 2 x 3 = 2^3 x 3 x 5
Now, we just select each different factor having the highest power...so we have
2^3 x 3^2 x 5 = 8 x 9 x 5 = 360
And that's the GCF