Polynomial or not a polynomial? 1) x4+3x3−5x2−7x+20 2) x3−2x2+x−12 3) x2+3x5−6x+12x3 4) x−3−x−2−6x−1+84x√3−x√−20 5) 4x√3−x√−20 6) 5x3−1x2+8x−40 select "p" for polynomial and select "np" for not a polynomial when answering