Question

25v^2+80vt+64t^2

Answer 1

Are you asked to factor?

Answer 2

(5v+8t)^2

Answer 3

It could be of the form (a+b)²
To check if it is, just remember that (a+b)²=a²+2ab+b².
So...if it is this form, you should have squares as outer terms.
Well...25v² is (5v)² and 64t² is (8t)².

So we are close to deciding it is (5v+8t)², BUT: we need to check if the middle term ik ok as well: it has to be 2*a*b

Here that would mean: 2*5v*8t

I leave it to you you decide...