What is the greatest common factor of 8x and 40y?

The greatest common factor (GCF) of 8x and 40y is 8.

To find the GCF, we need to find the highest power of each common factor in both terms.

In the case of 8x, the factors are 2 (from 8) and x (from x). The highest power of 2 is 3 (as 2^3 = 8) and the highest power of x is 1 (since x has a power of 1 in the term).

For 40y, the factors are 2 (from 40) and y (from y). The highest power of 2 is 3 (as 2^3 = 8) and the highest power of y is 1 (since y has a power of 1 in the term).

Therefore, the GCF of 8x and 40y is the product of the highest power of each common factor, which is 2^3 * 1 = 8.