The zeros of the quadratic polynomial are -5 and -3.We know that if a quadratic polynomial has zeroes at -5 and -3,(x + 5) and (x +3 ) are the factors of the resultant polynomial, and the resultant polynomial can be written in the form$(x + 5)(x + 3) = x^2 + 8x + 15$So, there is only one quadratic polynomial that has zeroes -5 and -3, and it is$x^2 + 8x + 15$