Find the value of C that will make 25x^2-40x+c a perfect trinomial.

Answer 1

I suppose what you mean by a perfect trinomial is a perfect square, in which case c has to be a perfect square in such a way that
25x^2-40x+c = (5x-4)^2
Can you find c?

Answer 2

The answer is 16 because when you use FIOL for (5x-4)(5x-4) you get 25x^2 -20x-20x+16.Then you simplify to 25x^2-40x+16 to your original problem with the answer of 16 in the problem.

FIOL is multiplying...
the FIRST term
then INNER terms
then OUTER terms
finally your LAST terms.

Answer 3

16

Answer 4

16