How to understand Cu (a ∩ b) = (CUA) ∪ (cub)?

How to understand Cu (a ∩ b) = (CUA) ∪ (cub)?

Thank you. I'll think about it first

How to understand this? Cu (a ∪ b) = (CUA) ∩ (cub)

I'll draw a picture for you to understand

How to calculate two X in the mathematical equation? 90 + 1 / 3x = x

Baby paper. 90 = X-1 / 3x

Let a = {- 4,2a-1, the square of a}, B = {9, a-5,1-a}, and a ∩ B = {9} be known?

When 2a-1 = 9, a = 5, but 1-A = - 4 ∩ a ∩ B = {- 4,9}, ∩ is omitted
When the square of a = 9, a = 3 or - 3
When a = 3, 2a-1 = 5, a-5 = - 2, 1-A = - 2 are consistent with the meaning of the question
When a = - 3, 2a-1 = - 7, a-5 = - 8, 1-A = 4 are consistent with the meaning of the question
A = 3 or - 3
∵2a-1=9,∴2a=1+9,∴2a=10,∴a=5

1.169（a+b）²-121（a-b）²
2.（x-3）（x-5）+1
3.(2a-b)²+8ab
4.y²-2y-x²+1
5.x³+3x²-4x-12
6.6x²+5x-4
7.（x²-2x）²+2(x²-2x)+1
8.（x²+3x+3）（x²+3x+5）+1
9.（m+n）²-4（m+n-1）

1,(13a+13b+11a-11b)(13a+13b-11a+11b)=(24a+2b)(2a+24b)=4(12a+b)(a+12b)2,x²-8x+15+1=x²-8x+16=(x-4)²3,4a²-4ab+b²=8ab=4a²+4ab+b²=(2a+b)²4,y²-2y+1-x²=(y-1)...

Factorization of several elementary one~
1.5m^2(a-b-c)+20m^4(b+c-a)
2.a^4-1/2a^2x^2y^2+1/16x^4y^4
3.9(x+3y)^2-25(x-3y)^2
4.4(2x-y)^2+21-12(2x-y+1)

1.
5m^2(a-b-c)+20m^4(b+c-a)
=5m^2(a-b-c)-20m^4(a-b-c)
=5m^2(a-b-c)(1-4m^2)
=5m^2(a-b-c)(1+2m)(1-2m)
two
a^4-1/2a^2x^2y^2+1/16x^4y^4
=(a^2-1/4x^2y^2)^2
=(a+1/2xy)^2(a-1/2xy)^2
three
9(x+3y)^2-25(x-3y)^2
=[3(x+3y)+5(x-3y)][3(x+3y)-5(x-3y)]
=(8x-6y)(-2x+6y)
=(-4)(4x-3y)(x-3y)
four
4(2x-y)^2+21-12(2x-y+1)
=4[(2x-y+1)-1]^2-12(2x-y+1)+21
=4(2x-y+1)^2-8(2x-y+1)+4-12(2x-y+1)+21
=4(2x-y+1)^2-20(2x-y+1)+25
=[2(2x-y+1)-5]^2
=(4x-2y-3)^2

y(x-2y）-x(2y-x)
Quarter x ^ 2-x + 1
9-a^2+2ab-b^2
9(n+m)^2-4(m-n)^2

①y(x-2y）-x(2y-x)
=y(x-2y）+x(x-2y)
=(x-2y)(y+x)
② 1 / 4x ^ 2-x + 1 (complete square)
=（1/2x）^2-1/2x×1×2+1^2
=(1/2x-1)^2
③9-a^2+2ab-b^2
=9-（a^2-2ab+b^2）
=3^2-(a-b)^2
=(3+a-b)(3-a+b)
④ 9 (n + m) ^ 2-4 (m-n) ^ 2 (square difference formula)
={3（n+m）}^2-{2(m-n)}^2
={3（n+m）+2（m-n）}{3(n+m)-2(m-n)}
=(3n+3m+2m-2n)(3n+3m-2m+2n)
=(5m+n)(5n+m)

Calculation: 39 × 37-13 × 34=______ ．

39 × 37-13 × 34 = 39 × 37-13 × 3 × 33 = 39 × (37-27) = 390

x2-5x+4=0

LZ's wrong way of asking questions should be:
(1) Factorization: x2-5x + 4 (this is a polynomial)
x2-5x+4=(x-1)(x-4)
Or (2) solve the equation: x2-5x + 4 = 0 (this is an equation)
(x-1)(x-4)=0;x1=1,x2=4.

Thirty factoring exercises, with difficulty

1.(4x+3y)2=16x2+9y2 ( )
The square of (a-b) is equal to the square of (B-A)
Single choice
4. If (2a + 3b) 2 = (2a-3b) 2 + () holds, then the formula in brackets is []
A.6ab B.24ab C.12ab D.18ab
5. If (X-Y) 2 = 0, the following equation is []
A.x2+y2=2xy B.x2+y2=-2xy C.x2+y2=0 D.2x2-y2=0
6. The following equation holds
A.(a-b)2=a2-ab+b2 B.(a+3b)2=a2+9b2
C.(a+b)(a-b)=(b+a)(-b+a) D.(x-9)(x+9)=x2-9
answer
1.×
2.√
3.√
4.B
5.A
6.C
judge
1.(4x+3y)2=16x2+9y2 ( )
The square of (a-b) is equal to the square of (B-A)
Single choice
4. If (2a + 3b) 2 = (2a-3b) 2 + () holds, then the formula in brackets is []
A.6ab B.24ab C.12ab D.18ab
5. If (X-Y) 2 = 0, the following equation is []
A.x2+y2=2xy B.x2+y2=-2xy C.x2+y2=0 D.2x2-y2=0
6. The following equation holds
A.(a-b)2=a2-ab+b2 B.(a+3b)2=a2+9b2
C.(a+b)(a-b)=(b+a)(-b+a) D.(x-9)(x+9)=x2-9
answer
1.×
2.√
3.√
4.B
5.A
6.C