If the value of polynomial (2 * x's square + ax-y + 6) - (2B * x's Square - 3x + 5y-1) has nothing to do with the value of letter X, find polynomial 3 (A's Square - 2ab-b's Square) We should use the ideas of junior one students! , find the value of polynomial 3 (the square of a - the square of 2ab-b) - (the square of 4 * a + the square of AB + b)

If the value of polynomial (2 * x's square + ax-y + 6) - (2B * x's Square - 3x + 5y-1) has nothing to do with the value of letter X, find polynomial 3 (A's Square - 2ab-b's Square) We should use the ideas of junior one students! , find the value of polynomial 3 (the square of a - the square of 2ab-b) - (the square of 4 * a + the square of AB + b)

(2 * x squared + ax-y + 6) - (2B * x squared - 3x + 5y-1)
=(2-2B)X^2+(A+3)X-6Y+7,
According to the meaning of the question, we get the equations
2-2B=0
A+3=0
The solution is a = - 3, B = 1,
∴3(A^2-2AB-B^2)-(4A^2+AB+B^2)
=-A^2-7AB-4B^2
=-9+21-4
=8.