`a,`
`Q(x)=` \(\dfrac{1}{2}x+\dfrac{2}{3}x^3-\dfrac{1}{3}x+\dfrac{5}{2}x^2-\dfrac{2}{3}x^3+1\)
`Q(x)=`\(\left(\dfrac{2}{3}x^3-\dfrac{2}{3}x^3\right)+\dfrac{5}{2}x^2+\left(\dfrac{1}{2}x-\dfrac{1}{3}x\right)+1\)
`Q(x)=`\(\dfrac{5}{2}x^2+\dfrac{1}{6}x+1\)
`b,` Bậc của đa thức: `2`
Hệ số cao nhất: `5/2`
Hệ số tự do: `1`
`c,`
`Q(-6)=`\(\dfrac{5}{2}\cdot\left(-6\right)^2+\dfrac{1}{6}\cdot\left(-6\right)+1\)
`= 5/2*36 -1+1 = 90-1+1=90`
`Q(1)= 5/2*1^2+1/6*1+1 = 5/2+1/6+1=8/3+1=11/3`
`Q(2)=5/2*2^2+1/6*2+1=5/2*4+1/3+1=10+1/3+1=31/3+1=34/3`