Since it is a perfect square trinomial, it is of the form:
a^2x^2-2abx+b^2 which simplifies to (ax-b)^2
Therefore:
sqrt(a)=sqrt(25)=5
sqrt(b)=sqrt(36)=6
Plug in a and b:
(ax-b)^2
(5x-6)^2
Test to make sure it did fit the formula:
-2abx=-60 (where x is 1)
-2(5)(6)=-60
-2(30)=-60
-60=-60
Answer:
(5x-6)^2