The greatest common factor is...
5a
I got this by...
10: 1,2,5,10
15: 1,3,5,15
25: 1,5,25
The GCF is 5 for the numbers.
For the a's, it's...
a: a
a^3: a×a×a
a^6: a×a×a×a×a×a
The GFC is a.
Then multiple 5 and a, and you get...
5a
The GFC is...
5a
Hope this helps!
Given:

To find:
Degree of the polynomial
Solution:
Degree of a polynomial:
The degree of the polynomial is highest power of the variable in the polynomial.

Here, the highest power is 4.
The degree of the polynomial is 4.