First simplify and then evaluate: 3x2y - [2xy2-4 (12xy-34x2y) + XY] + 3xy2, where x = 3, y = - 1

First simplify and then evaluate: 3x2y - [2xy2-4 (12xy-34x2y) + XY] + 3xy2, where x = 3, y = - 1

The original formula = 3x2y - [2xy2-2xy + 3x2y + XY] + 3xy2 = 3x2y-2xy2 + xy-3x2y + 3xy2 = XY2 + XY, substituting x = 3, y = - 1, the original formula = XY2 + xy = 0

First simplify and then evaluate: x2-2xy + Y2 is one fourth power of x2 + xy-2y2 - (1-xy2) (1 + XY2) - x2 △ y, where x = root 3-root 2, y = root 3-root 2

Solution
(X & # 178; + xy-2y & # 178;) / (X & # 178; - 2XY + Y & # 178;) - (1-xy & # 178;) (1 + XY) &# 178; - X & # 178; / (1 / y ^ 4) - is that it
=(x + 2Y) (X-Y) / (X-Y) &# 178; - (1-x & # 178; y to the fourth power) - X & # 178; y to the fourth power
=(x + 2Y) / (X-Y) - 1 + X & # 178; the fourth power of Y-X & # 178; the fourth power of Y
=(x+2y)/(x-y)-1
=(x+2y)/(x-y)-(x-y)/(x-y)
=(x+2y-x+y)/(x-y)
=(3Y) / (X-Y) - x ≠ y is wrong

What's the difference between XY2 and (XY) 2
I don't know. Does XY2 mean x + 2Y or 2 (x + y)?
If x = 3, y = 2, how to calculate these two questions?

XY2 is the square of x times y
(XY) 2 is the square of the product of x times y
If x = 3, y = 2
xy2=3*（2*2）=12
（xy)2=(3*2)*(3*2)=36