Question

[Ngọc Nguyễn]

cứu 

Answer 1

[Ng.T]

a)Ta có:

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

\(=3x^2+5x+1+2x^2+4x+2\)

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

\(=5x^2+9x+3\)

b) Ta có:

\(A\left(x\right)-B\left(x\right)=\left(3x^2+2x-4\right)-\left(-3x^2-2x+3\right)\)

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

\(=\left(3x^2+3x^2\right)+\left(2x+2x\right)-\left(4+3\right)\)

\(=6x^2+4x-7\)