5 will go into everything. That is one of the factors.
x^3 is in everything as well.
The highest common factor is 5x^3
[tex]\dfrac{5x^6}{5x^3} = x^(6-3) = x^3[/tex]
[tex]\dfrac{35x^4}{5x^3} = 7x^(4-3) = 7x[/tex]
[tex]\dfrac{15x^3}{5x^3} = 3*x^(3-3) = 3*1 = 3[/tex]
So the greatest common factor (determined by the last term) is 5x^3
And the left over polynomial is x^3 + 7x + 3
