Question

⒈已知多项式mx^4+〔m-2〕x^3+〔2n+1〕x^2-3x+n不含x^3和x^2项.请写出这个多项式,并求当x=-

Answer 1

1.多项式mx^4+〔m-2〕x^3+〔2n+1〕x^2-3x+n不含x^3和x^2项

m-2=0 m=2 2n+1=0 n=-1/2

2x^4-3x-1/2

当x=-1 2x^4-3x-1/2=2+3-1/2=9/2

2.2x^m-〔nx-2〕+3是三次二项次

m=3 n=0