It is known that the polynomial (A-2) x ^ 4 + 2x-1 / 2x ^ B-B about X is a quadratic trinomial. When x is equal to - 2, find the value of the quadratic trinomial Just now I saw a few. They said that a should be zero, but even if a is zero, then the fourth power of X is still four. Why is it quadratic?

It is known that the polynomial (A-2) x ^ 4 + 2x-1 / 2x ^ B-B about X is a quadratic trinomial. When x is equal to - 2, find the value of the quadratic trinomial Just now I saw a few. They said that a should be zero, but even if a is zero, then the fourth power of X is still four. Why is it quadratic?

(a-2)x^4+2x-1/2x^b-b
Is a quadratic trinomial
(a-2)x^4 =0
a=2
1 / 2x ^ B is quadratic
b=2
therefore
(a-2)x^4+2x-1/2x^b-b
=2x-1/2x^2-2
=4-2-2
=0

If the quadratic power of the polynomial MX + 2nxy-x + X - 2XY + y about X, y does not contain a quadratic term, then what is the value of 3m-2n

∵mx²+2nxy-x+x²-2xy+y
＝(m+1)x²+(2n-2)xy-x+y
If there is no quadratic term in the result, then
m+1=0,2n-2=0
∴m=-1,n=1
∴3m-2n
=3×(-1)-2×1
=-3-2
=-5

If the polynomial MX & sup2; + 2nxy-x + X & sup2; - 2XY + y does not contain quadratic terms about X and y, the value of M and N can be obtained
I can make up for it,

∵ does not contain quadratic terms about X, y
∴m+1=0, 2n-2=0,
The solution is m = - 1, n = 1