Question

Which value of c makes y^2+8y+c a perfect square A. 4 B.16 C.64 D.8

Answer 1

$y^2+8y+c \\ \\ c=(\frac{b}{2})^2=(\frac{8}{2})^2=4^2 = 16 \\ \\y^2+8y+16 = (y+4)^2 \\ \\Answer : \ B. \ \ 16$