a4-26a2+169
If you mean a^4 - 26a^2 + 169
then it looks like you have a perfect square.
The fact that the first and last terms were perfect squares gave me that clue.
Give it a try, it is quite simple
sqrt a^4 = a^2.
Sqrt 169 = 13.
solution: (a^2 - 13)^2.
check:
(a^2 - 13)^2 = a^4 - 26a^2 + 169.
To solve the expression a^4 - 26a^2 + 169, we can factor it as a perfect square trinomial.
Let's rewrite the expression as (a^2)^2 - 2ab + b^2, where b = 13.
By comparing this to the general form of a perfect square trinomial, (x - y)^2 = x^2 - 2xy + y^2, we can see that a^4 - 26a^2 + 169 is the square of the binomial (a^2 - 13)^2.
So, the simplified form of the expression is (a^2 - 13)^2.