Given x + y = 5, xy = 6, find (x + 1) (Y-1)

Given x + y = 5, xy = 6, find (x + 1) (Y-1)

x=5-y
(5-y)*y=6
x=-6 y=-1
(x+1)(y-1)=10

Given x-xy = 5, xy-y = - 3, find the value of X + y-2xy

From the question: x = 5 + XY, y = XY + 3
So: x + y = 8 + 2XY
X + y-2xy = 8 + 2xy-2xy = 8

Given X-Y = - 3, xy = 2, then the value of 2xy-x + y is
Ask to have the idea in the process of solving the problem, the answer already know, just don't know how to understand, should accord with the knowledge of grade one

2xy-x+y
=2xy-(x-y)
=2x2-(-3)
=7

The formula of the application problem of the equation of one degree with one variable (detailed)
Detailed formula. Comprehensive
To schedule... Match... And so on... Formula

Speed x time = distance
Work efficiency x time = total work
Unit price x quantity = total price
Yield per unit area X quantity = total yield
ax²+bx+c=0
When B & sup2; - 4ac > = 0, there are two roots
x1=(-b+√(b²-4ac))/2a
x2=(-b-√(b²-4ac))/2a
When B & sup2; - 4ac

How many hours does it take to complete all the work?

1÷（12.5%÷1/2）
=4 hours

4.5 cubic decimeter = () l () ml

4.5 cubic decimeter = (4) liter (500) ml
1 cubic decimeter = 1 liter = 1 000 ml

Knowledge points of unit 11, Volume 2, Grade 7, PEP
All right, come on, please

Explanation of unit 11 knowledge points
TV shows soap opera sitcom (situation combination) a combination an action movie a documentary a teller
Beijing Opera talk show animal world tell it like it is law today game show CCTV news in 30 minutes man and nature, cooking around China lucky 52 arts news sports show culture China Weekend Talk- A 13-year-old boy wearing colorful clothes, What do you think of soap operations / sports shows? I can't stand / don't mind / like / love / have / them. 2. What does she think of "hilltop high) / Amanda? She doesn't like it / her
1. What do you think of...? what do you think of (v. verb) "wear, wear, wear". Translate different Chinese meanings according to different objects
Wear earrings wear a dress wear a watch
Wear a beard wear long hair
2. Think "think, think, think" (v. verb) can be combined with many prepositions to form a new meaning
My mother always thinks of everything. He is thinking about going to China
My brother likes to play soccer. My brother likes to play soccer
(2) My brother doesn't like to play soccer
I don't like it, either.
In general, too and either are placed after the sentence and also before the verb
We also love talk shows. We also like talk shows. 4. A third - year - old boy. In this structure, year is singular and hyphen, which is used as attributive. E.g. a five - month - old baby a one - way road a three - meteree 200 - word - long article 5, Enjoy) enjoy is followed by a noun, pronoun or gerund, I love watching the soap operas. But we can't say: I enjoy to watch the soap operas. We can only say: I like / love to watch the soap operas. Welcome to sp Welcome to China. Welcome home. Welcome n. The people in Tibet game a warm welcome. Welcome adj. You are welcome. A welcome movie star Can you stand the soap opera? I can't stand staying at home all the day long
Do / would you mind my having breakfast in the classrom / opening the window? Never mind / not at all; I'm sorry / sorry, but I do. 9. Find students who agree with you
The girl is Emmy. The girl is wearing a colour dress. The girl who is wearing a colour dress is Emmy. Can you find my pen that / which I thought last weekend? B: agree with sb. Agree on sth (suggestion, plan) agree with sb on sth Agree with sb. On the whole
I agree with him. I agree with him on this problem. Do you agree on my suggestion?
He agreed to go to the movies with me. 10. Ask students about fashion. Ask sb sth
You can ask me questions after class. You can ask me about soap operations. Ask sb to do sth
11. I showed each students six things. A: show sb sth. show sth to sb
B: Each (pronoun), each (adj). The difference between every (adj)
Each (one) of us. Everyone of us. 12. Some of their answers are interested
Some of/ a lot of/ most of/ each of/ every one of/ many of/ much of
Here is + singular, here are + complex
Article in the school magazine
15.Can you please put my letter in next month’s magazine?
A: Can / could / will you please do sth?
B: Put put sth + prepositional phrase
put the book on my desk. Put the food in the fridge.
Put on, put down, put up, put away I can't stand the idea that old people can't be beautiful
That's a good idea
17. Clothes clothing cloth difference: clothes refers to specific clothes, which can not be used as singular or combined with numerals
Clothing is the general term of clothing. It is a collective noun without plural
Clothing can keep us warm. It means "cloth", "wool", "silk" (especially cloth and wool)
Tablecloth is a tablecloth

There are 1 red ball, 1 yellow ball and 1 white ball in the pocket. There are () different possibilities to feel the color of a ball from the pocket
A. 1 species B. 2 species C. 3 species

There is a red ball, a yellow ball and a white ball in the pocket. If you feel a ball from the pocket, you can feel the color of the ball in three different ways: red, yellow and white

How many square kilometers is 500 hectares? How many square meters is 3 hectares

500 ha = 5 km2, 3 ha = 30 000 m2

guess lantern riddles
Let's review below
Work hard and enjoy yourself
When you are angry, you are angry
All sides of the fence, please do not enter ()
One is that dogs don't look like dogs, the other is that non dogs look like dogs
Put in two pills to make two pills
1. The shape of the solid formed by six cubes is □
□□□□
From the left, the shape is □
□□
What is the shape of this solid? How many cubes does it need at least? How many cubes does it need at most?
2. When a ball falls from high altitude, it bounces 27 meters for the first time, 18 meters for the second time, 12 meters for the third time, 8 meters for the fourth time, and how many meters for the fifth time?
3. A cube with an edge length of 6cm is painted red and cut into 8 pieces. How many square centimeters is the sum of the uncolored areas of each piece?
4. Party A, Party B and Party C are the same car. It is agreed that everyone should share the fare. Party A will get off at 1 / 3, and Party B will get off at 1 / 3
Get off at 2 / 3 of the bus, and C will take the bus to the destination. He will pay 90 yuan in total. How much should Party A and Party B pay C?
Math question 1 is not clear
From the front, the shape of the solid formed by six cubes is □
··················□□□□
From the left, the shape is □
·······□□
·= Space
lydia_ Leung, formula

Lantern riddle: the first is the word "Fei", the second is the word "Jia", the third is the word "Xi", the fourth is the word "Hu", the fifth is the word "you", and the sixth is the word "CE". The first picture of mathematics is composed of six cubes. There's no shape to name. It's just right to use six pendulums