<PRE><B>Question 892919</B>
1. X^4+64y^4

3. X^4-11x^2y^2+y^4

1.(X^2)^2+(8y^2)^2 +2X^2.8Y^2-2X^2.8y^2   by adding and subtracting equal values
by formula
(x^2+8y^2)^2-16X^2y^2
(x^2+8y^2)^2-(4Xy)^2  we know identity A^2-B^2=(A-B)(A+B)
(x^2+8y^2-4Xy)(x^2+8y^2+4Xy) 

3. X^4-11x^2y^2+y^4
  (X^2)^2+(Y^2)2-2X^2y^2+2X^2Y^2-11x^2 y^2
(X^2-Y^2)^2-9X^2 Y^2
(X^2-Y^2)^2-(3X Y)^2
(X^2-Y^2-3X Y)(X^2-Y^2+3X Y)
























9</PRE>