Question

For making (x^4 - 11x^2y^2 + y^4) a perfect
square, the expression to be added is
​

Answer 1

Answer:

the expression to be added is 9x^2y^2.

Step-by-step explanation:

if we add 9x^2y^2 to the given polynomial the expression will be

x^4 -11x^2y^2+y^4 +9x^2y^2

x^4-2x^2y^2+y^4

(x^2-y^2)^2

which is a perfect square