If (x+y)³-(x-y)³-6y(x²-y²)=ky² then k=

10

The expression x⁴+4 can be factorized as

11

If 3x=a+b+c, then the value of (x-a)³+(x-b)³+(x-c)³-3(x-a)(x-b)(x-c) is

13

Ifx³-3x²+3x-7=(x+1)(ax²+bx+c), then a+b+c=

14

The value ofis