Factorization factor (a to the second power - B to the second power) + (3a-3b) Writing process, thank you

Factorization factor (a to the second power - B to the second power) + (3a-3b) Writing process, thank you

(2 of A-2 of B) + (3a-3b)
=(a-b)(a+b)+3(a-b)
=(a-b)(a+b+3)

The second power of factorization 3a to the second power of factorization 3B

How to factorize (x + y) - 4 (x + Y-1) (x + 1 / 4) - 2x (x + 1 / 4) + X
Write the process

Here are two questions: 1) (x + y) & # 178; - 4 (x + Y-1) = (x + y) & # 178; - 4 (x + y) + 4 = (x + y + 2) & # 178; 2) (X & # 178; + 1 / 4) & # 178; - 2x (X & # 178; + 1 / 4) + X & # 178; = (X & # 178; + 1 / 4-x) & # 178; = (x-1 / 2) ^ 4

2010x+2011y=2010,2011x+2010y=2011

x=1,y=0
X-Y = 1 201x-2010y = 2010
Add to the second formula to get 4021 x = 4021 x = 1 y = 0

The probability that the absolute value of the mean difference of two independent random samples with the capacity of 10 and 15 in population xn (20,3) is greater than 0.3

The mean value of two independent random samples with the capacity of 10 and 15 is represented by X (10) and X (15)
X(10)~N(20,3/10),X(15)~N(20,1/5)
Because the two random samples are independent, so
E(X(10)-X(15))=E(X(10))-E(X(15))=20-20=0
D(X(10)-X(15))=D(X(10))+D(X(15))=3/10+1/5=1/2
That is x (10) - x (15) ~ n (0,1 / 2)
P(|X(10)-X(15)|

If the left side of the quadratic equation x 2 + m x + m + 2 = 0 with respect to X is exactly a complete square, we can find the value of M

∵ on the left side of the univariate quadratic equation x2 + MX + m + 2 = 0, there is a complete square formula, which is a complete square formula, ∵ m + 2 = (± m2) 2, that is m2-4m-8 = 0, the solution is m = 2 + 23 or M = 2-23, answer: the value of M is 2 + 23 or 2-23

D. E and F are the midpoint of each side of △ ABC respectively. What is the relationship between the median line AD and the median line ef?

EF split ad equally
By connecting ed and DF, it can be known that ED is parallel and equal to AF, and the quadrilateral AEDF is a parallelogram
Ad and EF are diagonals, according to the parallelogram diagonals, we can get the answer

9 to the x power + 2 * 3 to the X + 1 power - 27 is less than 0 (* is a multiplication sign). Please write down the process, use elimination method, and save time

9^x+2*3^(x+1)-27

Comparison of 1111 out of 1111 and 1111 out of 11111

111/1111=1-1000/1111=1-10000/11110
1111/11111=1-10000/11111
Compare the two formulas, 10000 / 11110 > 10000 / 11111
So - 10000 / 11110

Find the minimum value of the function y = 94 (1 + 4x2) + x2

The function y = 94 (1 + 4x2) + x2 = 91614 + x2 + (x2 + 14) − 14 ≥ 2916 − 14 = 54, when (14 + x2) = 91614 + X2, i.e. x = ± 22, the equal sign holds. Y ≥ 54, i.e. the minimum value of the function is 54