Easy
quadratic means 2nd degree
means highest power of exponent is 2
so like x^2
first one
we have 3x^3, that is 3rd degree,nope
2nd one
we have 8x^4, nope, that is 4th degree
3rd one
we have -x^2, yep
4th one, we have 9x^4, that is 4th degree
answer is 3rd one or p(x)=-5x-x^2
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