a/ \(M=3x^6y+\frac{1}{2}x^4y^3-4y^7-4x^4y^3+11-5x^6+2y^7-2\)
\(=3x^6y+\left(\frac{1}{2}x^4y^3-4x^4y^3\right)-\left(4y^7-2y^7\right)+\left(11-2\right)-5x^6\)
\(=3x^6y-\frac{7}{2}x^4y^3-2y^7+8-5x^6\)
→ Bậc: 7
b/ Thay x = 1; y = -1 vào M ta có:
\(M=3.1^6\left(-1\right)-\frac{7}{2}.1^4.\left(-1\right)^3-2.\left(-1\right)^7+8-5.1^6\)
\(=-3+\frac{7}{2}+2+8-5\)
\(=\frac{11}{2}\)