Segment addition postulate please help me

Find the condition that the zeros of the polynomial f(x) = x^3+3px^2+3px+r may be in a. p.

Alina fully simplifies this polynomial and then writes it in standard form. xy2 – 2x2y + 3y3 – 6x2y + 4xy2 if alina wrote the last term as 3y3, which must be the first term of her polynomial in standard form? xy2 5xy2 –8x2y –2x2y

Write the equation in general quadratic form: plz !