Answer:
D. 64
Step-by-step explanation:
Hello,
you know the discriminant and that if it is equal to 0 then the polynomial is a perfect square. So we need to solve
[tex]b^2-4ac = 0[/tex]
in this example it means that we need to find c so that
[tex]16^2-4c=0\\<=>4c = 256\\<=>c=256/4=64\\[/tex]
so the solution is 64
and we can verify is as
[tex]x^2+16x+64=x^2+2*8*x+8^2=(x+8)^2[/tex]
hope this helps
