Given the square of (2x-y-1) + | - x + 2y-3 | = 0, find the value of X + y

Given the square of (2x-y-1) + | - x + 2y-3 | = 0, find the value of X + y

Because the square of (2x-y-1) + | - x + 2y-3 | = 0,
So 2x-y-1 = 0, - x + 2y-3 = 0
The sum of the two formulas gives x + y-4 = 0
So x + y = 4

The square of x equals six. What is x equal to?
If the square of x equals six, then x =? No root. What is x, not six

4494897428, which should be an infinite acyclic decimal

Please answer with equation!
1. If a commodity is sold at a 20% discount on the marked price, how much profit can it make if it is sold at the original price?
2. If the purchase price of a commodity is 50 yuan, in order to earn 20% profit, what is the price of the commodity
3. If two goods are sold for 84 yuan, one of them loses 20% and the other makes 40% profit, then whether the two goods will make a profit or lose money after they are sold, how much profit and how much loss?
4. If the price of a commodity is 220 yuan and the profit is 10% after 10% discount, how much is the purchase price of the commodity?
5. The purchase price of a certain commodity is 800 yuan, and the price is 1200 yuan when it is sold. Later, due to the backlog of the commodity, the commodity is ready to be sold at a discount. If you want to get 5% profit, how much discount should you give?
6. A commodity will increase the cost of a certain garment by 40% and then sell it at 20% discount. As a result, each garment will make a profit of 15 yuan. What is the cost price of each garment?
7. If a store sells a sweater of a certain brand at 20% discount, it can still make a profit of 20%. If the purchase price of the sweater of that brand is 100 yuan per piece, how much is the price per piece?
8. A certain commodity is ready to be sold at a discount due to season change. If it is sold at a 25% discount, it will lose 25 yuan. If it is sold at a 10% discount, it will earn 20 yuan. What is the price of this commodity?
9. Party A and Party B ride an electric car and travel from two places 45 away from each other at the same time. They meet in two hours. It is known that Party A travels 2.5km more than Party B every hour. How many kilometers does Party A and Party B travel each hour?
10. When an aircraft flies between a and B, it takes 5.5 hours from a to B and 6 hours from B to A. if the wind speed is 24 kilometers per hour, what is the distance between a and B?

(1) If the price is set as "1" and the profit is x, then (1 + x) × 80% = 1 + 20%, the solution is: x = 50%. A: the profit is 50%. B: if the price is set as X, then x △ 50 = 1 + 20%, the solution is: x = 60. A: the price is 60 yuan. (3) if the price of commodity a is X Yuan and that of commodity B is y yuan, then x × (1-20%) = 84, y × (1 + 40)

Given the first n terms and Sn = 54, the first 2n terms and s2n = 60 of the equal ratio sequence {an}, then the first 3N terms and s3n = 60___ ．

∵ the sequence {an} is an equal ratio sequence; Sn, s2n Sn, s3n-s2n are equal ratio sequences; s3n-s2n & nbsp; s2n Sn = s2n snsn, that is s3n-6060-54 & nbsp; = 60-5454; s3n = 6023, so the answer is 6023

Two thirds of the boys in class 6 (1) are girls, and the number of girls is a few percent of the boys

（2/3）/（3/4）=8/9
The number of girls is 8 / 9 of that of boys

As shown in Figure 1, the cross section of the dam is an isosceles trapezoid ABCD, the slope of slope AB is 1: root sign 3, the horizontal width of slope AB is 3 times of root sign 3 m, and the upper and bottom width ad is 4 M
What is the slope angle B, dam height AE and dam bottom width BC?

tgB=1/√3
B=30
AE=3√3/√3=3
BC=4+2*3√3=4+6√3

A correspondent needs to deliver the letter to a certain place within the specified time. He can get there 24 minutes earlier by cycling 15km per hour. If he travels 12km per hour, he will be 15 minutes late. What is the original time? How far is it for him to go somewhere?

Suppose the specified time is x hours. 15 × (x-2460) = 12 (x + 1560), the solution is: x = 3, when x = 3, 15 × (x-2460) = 39. Answer: the original time is 3 hours, and the distance to a certain place is 39 kilometers

What is the eigenvalue of determinant and how to find the rank of matrix

In linear algebra, let a be a matrix of order n, if the number λ and the n-dimensional nonzero column vector x make the relation
Ax = λ x holds, then such a number λ is called the eigenvalue of square matrix A
To find the rank of a matrix, we should change the first column into only one number which is not zero. If there is only one number in the second column, it will be first order when we draw a ladder. In this way, we can draw until a certain row is all zero. The number of rows above this row is the rank of the matrix

01.2.3.4.5.6.7.8.9. This is a number, which should be filled in the box below. Each number can only be used once, so that the following three formulas are true

Although I can't see the question, I've done something similar. Is this the answer
4 3 8
9 5 1
2 7 6

Let a and B be nonzero matrices of order n, and ab = O, then what conditions should the rank of a and B satisfy?

R(A)+R(B)