A∈A is -4
X+a= 1→x= 1-a∈(0,5);
Then b = {x │ 0
Then a ∩ b = {x │ 0
2
A∩B={- 1}, with:
1+p+q = 0;
1-p-2q = 0;
To solve this system of equations:
p =-3; q=2。
Namely: A={x│x? -3x+2=o},B={x│x? +3x-4=0}
Solve the equation by decomposition:
A={ 1,2},B={ 1,-4 };
Then A∪B={ 1, 2, -4}
three
The key to solve this problem is to understand the meaning of the problem, UA = {5}, which means 5∈U, but 5A, so A2+2A-3 = 5.
| 2a- 1 | ≠ 5 and | 2a- 1 | ∈ u
Solution: ua = {5}, ∴5∈U and 5a.
∴ A2+2A-3 = 5, and the solution is A = 2 or A =-4.
When a = 2, | 2a- 1 | = 3 ≠ 5,
When a =-4, | 2a- 1 | = 9 ≠ 5 but 9U
∴ A =-4 (shed) ∴ A = 2.
four
There is an error in the question: x? +mx+n=0 is a quadratic equation, so there can only be two elements in a at most;
So the complement set of A in U should have at least two elements.