Verify that `-(-x)=x` for `x=2/15`

Verify that -(-x)=x for x=(-12)/(11)

Verify that -(-x)=x for x=(5)/(17)

Verify that -(-x)=x for x= (-13)/17

Verify that x^3 + y^3 + z^3- 3xyz=1/2 (x+y+z)[(x-y)^2+(y-z)^2+(z-x)^2]

Verify that 3, -1, -1/3 are the zeroes of the cubic polynomial p(x) = 3x^(2)-5x^(2)-11x-3 , and then verify the relationship between the zeroes and the coefficients.

Verify that 2, -3 and -4 are the zeroes of the cubic polynomial x^3+5x^2-2x-24 and check the relationship between zeroes and the coefficients.

Verify that 1,-2 and -3 are the zeroes of the cubic polynomial x^3+4x^2+x-6 and check the relationship between zeroes and the coefficients.

Verify that 1, -1 and -3 are the zeroes of the cubic polynimial x^(3)+3x^(2)-x-3 and check the relationship between zeroes and the coefficients.

Verify that 4,-1, -1/4 are the zeroes of the cubic polynomial 4x^3-11x^2-19x-4 .

Verify whether 2x ^(4) - 6x ^(3) + 3x ^(2) + 3x -2 is divisible by x ^(2) - 3x +2 or not ? How can you verify using Factor Theorem ?