Bài 2 :
`a)A(1)=2.1^4+3.1+1^2+2.1-6`
`A(1)=2+3+1+2-6`
`A(1)=2`
`b)A(x)=2x^4+3x+x^2+2x-6`
`A(x)=2x^4+x^2+5x-6`
`B(x)=5x^2-3x+2x^4-6x^2+1`
`B(x)=2x^4-x^2-3x+1`
`c) P(x)=A(x)+B(x)`
`P(x)=(2x^4+x^2+5x-6)+(2x^4-x^2-3x+1)`
`P(x)=2x^4+x^2+5x-6+2x^4-x^2-3x+1`
`P(x)=(2x^4+2x^4)+(x^2-x^2)+(5x-3x)+(-6+1)`
`P(x)=4x^4+2x-5`
`Q(x)=A(x)-B(x)`
`Q(x)=(2x^4+x^2+5x-6)-(2x^4-x^2-3x+1)`
`Q(x)=2x^4+x^2+5x-6-2x^4+x^2+3x-1`
`Q(x)=(2x^4-2x^4)+(x^2+x^2)+(5x+3x)+(-6-1)`
`Q(x)=2x^2+8x-7`
$\text{Xin hay nhất }$
