Answer:
:)
Step-by-step explanation:
[tex]M = 3x^2y^3-4xy +x^3y\\\\2M = 2 \times (3x^2y^3-4xy +x^3y) \\\\[/tex]
[tex]= 6x^2y^3 - 8xy + 2x^3y[/tex]
[tex]N = -2x^3y + 6x^2y^3 -8xy -8[/tex]
[tex]= 6x^2y^3 -8xy -2x^3y -8[/tex] [tex][ re-arranging \ the \ terms][/tex]
a)
[tex]2 M - N = ( 6x^2y^3 -8xy +2x^3y) - (6x^2y^3-8xy -2x^3y - 8)[/tex]
[tex]= 6x^2y^3 - 8xy +2x^3y -6x^2y^3 +8xy +2x^3y + 8\\\\= 4x^3y +8[/tex]
b)
[tex]2M - N \ for \ x = -1 \ and \ y = 2: (4(-1)^3\times (2)) + 8 = -8 + 8 = 0[/tex]
