Question

Answer 1

Câu 1:

\(a,A\left(x\right)+B\left(x\right)=x^3+2x^2-4x-4+x^3+x^2-6x-4=2x^3+3x^2-10x-8\\ b,A\left(x\right)-B\left(x\right)=x^3+2x^2-4x-4-x^3-x^2+6x+4=x^2+2x\)

Câu 2:

\(Q\left(x\right)=P\left(x\right)+Q\left(x\right)-P\left(x\right)=2x^4-3x^3+5x^2+3x+1-2x^4+2x^3+x-1=-x^3+5x^2+4x\)

Answer 2

Câu 1 mình vừa làm rồi 

Câu 2 : 

Ta có : \(P\left(x\right)+Q\left(x\right)=2x^4-3x^3+5x^2+3x+1\)

\(\Rightarrow Q\left(x\right)=2x^4-3x^3+5x^2+3x+1-2x^4+2x^3+x-1\)

\(=-x^3+5x^2+4x\)

Answer 3

Câu 1:

a) A(x)+B(x)=x³+2x²-4x-4+x³+x²-6x-4=2x³+3x²-10x-8.

b) A(x)-B(x)=x³+2x²-4x-4-(x³+x²-6x-4)=x²+2x