a: \(A\left(x\right)=-11x^5+4x-12x^2+11x^5+13x^2-7x+2\)
\(=\left(-11x^5+11x^5\right)+\left(-12x^2+13x^2\right)+4x-7x+2\)
\(=x^2-3x+2\)
Bậc là 2
Hệ số cao nhất là 1
b: \(M\left(x\right)=A\left(x\right)\cdot B\left(x\right)=\left(x-1\right)\cdot\left(x^2-3x+2\right)\)
\(=x^3-3x^2+2x-x^2+3x-2\)
\(=x^3-4x^2+5x-2\)
c: Đặt A(x)=0
=>\(x^2-3x+2=0\)
=>(x-1)(x-2)=0
=>\(\left[{}\begin{matrix}x=1\\x=2\end{matrix}\right.\)