Question

P(x)=5-2x^3+1/4x^2    Q(x)=-3/4x^2+x^3+5+x

R(x)=1+4x^3-2x.     Tính p(x)+Q(x)-R(x)   P(x)-Q(x)+R(x)

Answer 1

\(P\left(x\right)+Q\left(x\right)+R\left(x\right)\)

\(=-2x^3+\dfrac{1}{4}x^2+5-\dfrac{3}{4}x^2+x^3+x+5+R\left(x\right)\)

\(=-x^3-\dfrac{1}{2}x^2+x+10+4x^3-2x+1=3x^3-\dfrac{1}{2}x^2-x+11\)

\(P\left(x\right)-Q\left(x\right)+R\left(x\right)\)

\(=-2x^3+\dfrac{1}{4}x^2+5+\dfrac{3}{4}x^2-x^3-5-x+R\left(x\right)\)

\(=-3x^3+x^2-x+4x^3-2x+1=x^3+x^2-3x+1\)

Answer 2

`P(x)+Q(x)-R(x)=5-2x^3+1/4x^2-3/4x^2+x^3+5+x-1-4x^3+2x`

            `=-5x^3-1/2x^2+3x+9`

`P(x)-Q(x)+R(x)=5-2x^3+1/4x^2+3/4x^2-x^3-5-x+1+4x^3-2x`

                   `=x^3+x^2-3x+1`