Complete-the-square-in-the-expression-y-2-8y-9k-and-hence-find-the-value-of-k-that-makes-it-a-perfect-square-

Question Number 49823 by pieroo last updated on 11/Dec/18

Complete the square in the expression

y^{2} + 8 y + 9 k and hence find the value

of k that makes it a perfect square .

Answered by ajfour last updated on 11/Dec/18

{(y + 4)}^{2} = y^{2} + 8 y + 16

\Rightarrow 9 k = 16

\Rightarrow k = \frac{16}{9} .

Commented by pieroo last updated on 11/Dec/18

thanks sir

Answered by peter frank last updated on 11/Dec/18

from

b^{2} = 4 ac

64 = 36 k

k = \frac{16}{9}