1，{ x | x+2≤0 }∩{ x | x-3 & gt； 0}={x|x≤ -2 or | x >；; 3}

2. let the set a = {x | x >；; 0}，B = { x | x & lt3,},

A∪B={x|x∈R}

3. let the set a = {x | x >；; 1}，B={x|x≤- 1}，，

A ∪ b = {x | x ≤- 1 or x> 1}

4, let the set a = {x |- 1

a∪B = { x | x & gt； 1}

intersection

5. A = {x | 2-9 = 0} = {-3,3 3}(B = {x | x (x-3) = 0} {0,3} (bHow to calculate {0,3}? ),

Solve the equation x(x-3)=0 to get X 1 = 0 and X2 = 3.

6、Z∩Q=Z

7,{x|x^2-x=0}∩{0}={0, 1}∩{0}={0}

8. known sets a, b, a ∩ b. A={x|x≥-2}, B = {x | x & lt4}. a = { x | x ≥- 1 } B = { x | x & gt； 1}

If A={x|x≥-2}, b = {x | x.

If a = {x | x ≥-1} b = {x | x >; 1}, then a ∩ b = {x | x > 1}

supplementary set

9. Let the complete sets S={ 1, 2, 3, 4, 5,} and A={ 1, 5} find CsA and Cs(CsA). What's the difference between CsA and Cs(CsA) here?

CsA={2，3，4}Cs(CsA)={ 1，5}

CsA ..... The complement of set A under complete set S Cs(CsA) The complement of set CsA under complete set S is A.

10, let S={0, 1, 2,3,4}, A={ 1, 2,4}, B={ 1, 3}, then

CsA={0，3}，A∪CsB={0，2，4}，CsA∪B={0， 1，3}，CsB∪A={0， 1，2，4}

Let the complete set S=R, CsA{x|}x∈R, x≠ 1, 2,4}