What is the complete factorization of 4x^2-9y^4? a. 36(x^2-y^4) b. 4x^2(1-9y^4) c. (2x+3y^2)(2x-3y^2) d. (2x-3y^2)(2x-3y^2)

Use the difference of squares factor rule to get
4x^2-9y^4
(2x)^2-(3y^2)^2
(2x-3y^2)(2x+3y^2)

The final answer is choice C
Note: the order of the factors does not matter

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm