Complete set u = R, if a = {x | 3 ≤ x ＜ 10}, B = {x | 2 ＜ x ≤ 7}, find a ∩ B, a ∪ B, (CUA) ∩ (cub)

Complete set u = R, if a = {x | 3 ≤ x ＜ 10}, B = {x | 2 ＜ x ≤ 7}, find a ∩ B, a ∪ B, (CUA) ∩ (cub)

A∩B= =﹛x|2＜x≤7﹜,A∪B=﹛x|3≤x＜10﹜,(CuA）∩（CuB）=﹛x|x≤2,10≤x﹜
Set u = {x ≤ 10, X ∈ n}, a ∈ u, B ∈ u, and a ∩ B = {4,5,6}, (cub) ∩ a = {2,3} (CUA) ∩ (cub) = {7,8}
A（2,3,4,5,6）
B（0,1,4,5,6,9,10）
The complete set u = {positive integers less than 10} A is contained in U, B is contained in U, and (CUA) ∩ B = {1,8} a ∩ B = {2,3} cub = {4,6,9} find the set a and B
B=B∩U=B∩(A∪CuA)=(B∩A)∪(B∩CuA)=｛2,3｝∪｛1,8｝=｛1,2,3,8｝,
Because CUA = CUA ∩ u = CUA ∩ (B ∪ cub) = (B ∩ CUA) ∪ (CUA ∩ cub)
=｛1,8｝∪｛4,6,9｝=｛1,4,6,8,9｝,
So a = {2,3,5,7}
By the way, the last condition should be (CUA) ∩ (cub) = {4,6,9}
A problem of factorization
1. First decompose the factor, then calculate and evaluate
IR1 + IR2 + IR3, where R1 = 25.4, R2 = 39.2, R3 = 35.4, I = 2.5
=I(R1+R2+R3)
=2.5*100
=250
Given that 1 / a minus 1 / B is equal to 4, find the value of a-2ab-b of 2a-2b + 7ab
It's better to have a detailed idea
Because 1 / A + 1 / b = 4, 4AB = a + B. A and B1 / 4, and A0, B0
From (a-2ab-b) / (2a-2b + 7ab), substitute 4AB = a + B, and simplify,
(2a-6b) / (15a-b)
From 4AB = a + B, a = B / (4b-1) is obtained
(6b-2)/(b-4) (b0,b4,b1/4)
4ab-8ab
4ab-8a B = 4 (ab-2a b) = 4AB (b-2a)
If m power of a = 2, n power of a = 8, then (M + n) power of a =? 2a, M-N power of a =? 2A,
The (M + n) power of solution 1A = m power of a * n power of a = 2 * 8 = 16
M-N power of 2 a = m power of a △ n power of a = 2 △ 8 = 1 / 4
That is, the M-N power of 2A = 2 * 1 / 4 = 1 / 2
If the m power of a is 2 and the n power of a is 8, then the (M + n) power of a is 16;
M-N power of 2A = 2 × (m power of a △ n power of a) = 2 × (2 △ 8) = 1 / 2
Factoring a problem
1-(4x^2)-(4y^2)+8xy
Original = - (4x & # 178; - 8xy + 4Y & # 178; - 1)
=-[(2x-2y)²-1]
=-(2x-2y+1)(2x-2y-1)
1-(4x^2)-(4y^2)+8xy
=1-(4x^2-8xy+4y^2)
=1-(2x-2y)^2
=(1+2x-2y)(1-2x+2y)
If it helps you, please remember to adopt it_ Thank you
Given that the power a of 2 is equal to 5, and the power B of 3 is equal to 7, find the value of the power 2A + 3b of 2
2A + 3B power of 2
=The 2A power of 2 and the 3B power of x2
=(a power of 2) & #178; x7
=5²x7
=175
Factorization exercises in grade one of junior high school
(a+b)(a+b)+2a+2b+1
(a+b)(a+b)+2a+2b+1
=(a+b)²+2(a+b)+1
=(a+b+1)²
(a+b+1)^2
(a+b+1)(a+b)+1
(a+b)(a+b)+2a+2b+1
=(a+b)²+2(a+b)+1
=(a+b+1)²
(a + B + 1) square
(a+b)^2+(2a+2b)+1
=(a+b)^2+2(a+b)+1
=[(a+b)+1]^2
=(a+b+1)^2
=a^2+2ab+2b+2(a+b)+1
=(a+b)^2+2(a+b)+1
=(a+b+1)^2
Be a little clearer
(a+b)(a+b)+2a+2b+1
=(a+b)²+2(a+b)+1
=(a+b+1)²