Help with sum and product of roots. I'm having trouble with a question from my textbook relating to roots of an equation. This is it:
Let a and b be the roots of the equation:
$x^2-x-5=0$
Find the value of $(a^2+4b-1)(b^2+4a-1)$, without calculating values of $a$ and $b$.
What I do know however, is that the book has hinted towards sum and product of roots in which I have determined that the SUM OF ROOTS is $1$ and the PRODUCT OF ROOTS is $-5$. So really I'm just having difficulty finding the value. I don't want a direct answer can I have a few hints to get myself closer to getting the answer?

Hint expand the expression and use $a^3+b^3=(a+b)^3-3ab(a+b),a^2+b^2=(a+b)^2-2ab$ and then it's all easy.
