Define the operation a * B of set a and B = {x | x ∈ a or X ∈ B, and X ∉ a ∩ B}, then (a * b) * a is equal to () A. A∩BB. A∪BC. AD. B

Define the operation a * B of set a and B = {x | x ∈ a or X ∈ B, and X ∉ a ∩ B}, then (a * b) * a is equal to () A. A∩BB. A∪BC. AD. B

As shown in the figure, a * B represents the shadow. Let a * b = C. according to the definition of a * B, c * a = B, so (a * b) * a = B, so the answer is: D

Define the operation of set a and B as a * b = {x | x belongs to a and X does not belong to B}. Try to write an expression with set operation symbols "*" ∪ "∩" and hold for any set a and B

A*B=(AUB)∩CuB

Let a and B be two nonempty sets. The difference set between a and B is defined as A-B = {x | x ∈ A and X does not belong to B}
Prove whether the difference sets A-B and B-A are necessarily equal?

This question does not need to prove the process, according to the meaning of the set, it can be answered directly
A-B = {x | x ∈ A and X does not belong to B}
B-A = {x | x ∈ B and X does not belong to a}
So when a = B, A-B = B-A = empty set
When a ≠ B, A-B must not be equal to b-a

1、 Define the difference set A-B of a and B = {x | x ∈ A and X does not belong to B}. (1) let the total set be u, use the intersection, union and complement operations of the set to represent A-B and b-a;
(2) Let a = {0,1,2,3}, B = {1,2,4}, find A-B and b-a
2、 The definition of difference set of a and B is as follows: a = {x | x > 4}, B = {x | X|

(1) A-B=A∩(cuB） B-A=B∩(cuA)
2) Let a = {0,1,2,3}, B = {1,2,4}, A-B = {0,3}, B-A = {4}
It is known that a = {x | x > 4}, B = {x | x}|

If "*" operation is defined as a * b = AB + 2a, and (3 * x) + (x * 3) = 14

（3*x）+（x*3）=3x+2×3+3x+2x
So:
3x+2×3+3x+2x=14
8x+6=14
8x=8
x=1

The new operation * is defined as a * b = AB + 2a, if (a * x) + (x * 3) = 14, then the value of X is? (process)

(a*x)=ax+2a
(x*3)=3x+6
(a*x)+(x*3)=(ax+2a)+(3x+6)
(ax+2a)+(3x+6)=14
ax+3x+2a+6=14
x(a+3)=8-2a
x=2(4-a)/(a+3)

The operation of a set is known as u = {x | 0

CUA = {3,6,7,8,10}, Cub = {1,2,3,5,9}, CUA ∩ cub = {3}, CUA ∪ cub = {1,2,3,5,6,7,8,9,10}, Cu (a ∪ b) = {3}, Cu (a ∩ b) = {1,2,3,5,6,7,8,9,10}, equivalent set: CUA ∩ cub = Cu (a ∪ b)

The known sets a = {x | x + a > 0}, B = {x | BX0}, B = {x | BX}

（1）
A ∩ B = (3,4) indicates that b > 0
A=(-a,+∞),B=(﹣∞,1/b)
{-a=3
{1/b=4
a= - 3
b=1/4
（2）
A is a ray to the right, B is also a ray, but the two rays together are two rays with a point removed on the x-axis. Only the two end values are equal, that is - a = 1 / b = > AB = - 1

Define the operation "*" in the set of rational numbers, the rule is a * b = a + B 2, try to find the solution of equation 2 * (x * 3) = 1

∵ a * b = a + B2, ∵ x * 3 = x + 32; ∵ 2 * (x * 3) = 2 + X + 322; so 2 + X + 322 = 1, ∵ 2 + X + 32 = 2, ∵ x = - 3

Define the set a * b = {x | x ∈ a, and X? B} if a = {1,3,5,7} B = {2,3,5}, then the number of subsets of a * B is?
Why do subsets have empty sets?

Define the set a * b = {x | x ∈ a, and X? B} if a = {1,3,5,7} B = {2,3,5}, then a * b = {1,7}
The number of subsets of a * B is
Empty set, {1}, {7}, {1,7}
An empty set is a subset of any set