Question

M=3xyz-3x³+5xy-1 n=5x²+xyz-5xy+3-y

Tính M+N, M-N

Answer 1

đề bài là gì vậy bạn

Answer 2

 \(M + N = (3xyz – 3x^2 + 5xy – 1) + (5x^2 + xyz – 5xy + 3 – y)\)

      \(= 3xyz – 3x^2 + 5xy – 1 + 5x^2 + xyz – 5xy + 3 – y\)

      \(= (3xyz + xyz)+( –3x^2 + 5x^2) + (5xy – 5xy) – y + ( – 1+3)\)

      \(= 4xyz + 2x^2 – y + 2\)

 \(M – N = (3xyz – 3x^2 + 5xy – 1) – (5x^2 + xyz – 5xy + 3 – y)\)

      \(= 3xyz – 3x^2 + 5xy – 1 – 5x^2 – xyz + 5xy – 3 + y\)

      \(= (– 3x^2 – 5x^2) + (3xyz – xyz) + (5xy + 5xy) + y +(– 1 – 3)\)

      \(= –8x^2 + 2xyz + 10xy + y – 4.\)

\(N – M = (5x^2 + xyz – 5xy + 3 – y) – (3xyz – 3x^2 + 5xy – 1)\)

      \(= 5x^2 + xyz – 5xy + 3 – y – 3xyz + 3x^2 – 5xy +1\)

      \(= (5x^2 + 3x^2)+ (xyz – 3xyz)+( – 5xy – 5xy) + (3 + 1 )– y\)

      \(= 8x^2 – 2xyz – 10xy – y + 4.\)

Answer 3

M+N=(3xyz-3x³+5xy-1)+(5x²+xyz-5xy+3-y)

        =3xyz-3x³+5xy-1+5x²+xyz-5xy+3-y

        =(3xyz+xyz)+(-3x³)+(5xy-5xy)+(-1+3)+5x²-y

        =   4xyz+(-3x³)+2+5x²-y

M-N=(3xyz-3x³+5xy-1)-(5x²+xyz-5xy+3-y)

       =3xyz-3x³+5xy-1-5x²-xyz+5xy-3+y

       =(3xyz-xyz)+(-3x³)+(5xy+5xy)+(-1-3)-5x²+y

       =   2xyz+(-3x³)+10xy+(-4)-5x²+y