The structure of uncountable nouns

The structure of uncountable nouns

1、 Countable nouns are nouns that can be used to count. Countable nouns have singular and plural forms, such as: Desk desks, apple apples, etc, He is a factory worker. No one can see air. 3. Some, any, a lot of, lots of, etc. can be used before countable and uncountable nouns to express "some, any, a lot of, lots of, etc, There are some oranges on the desk. There is a lot of water in the bottle, This picture is very beautiful, There are two cups of tea on the table; How many apples are there in the box? How many tea is there in the cup? Note: how many pieces of bread are there on the plate?

What are uncountable nouns?

money,chicken,fish,water,bread,paper,news,meat,cake,coffee,snow,tea,milk,rice,traffic,homework,housework,age,hair,time,weather,wind,world,moon,sleep,luck,music,nature,ice,food,glass,gold,help,hope,peo...

On uncountable nouns
1.he often gives milk to me.
2.my teachers often give advice to us about our problems.
. because of about our problems?

He of en gives milk to me?
A: Yes
The singular of uncountable nouns can be used alone
My teachers often give advice to us about our problems?
A: Yes
Problems (plural of problems)

(4x+20)/4-(6x-20)/5=2

(4x+20)/4-(6x-20)/5=2
Remove bracket x + 5-6 / 5 x + 4 = 2
Merge - 1 / 5 x = - 7
x=35

9-18 is equal to?

-9

Solving fractional equation [(x + 2) / (x + 1)] + [(x + 8) / (x + 7)] = [(x + 6)] / [(x + 3)] + [(x + 4)} / [(x + 3)]

The first x + 3 to the right of the equal sign should be x + 5, right?
Split item: 1 + 1 / (x + 1) + 1 + 1 / (x + 7) = 1 + 1 / (x + 5) + 1 + 1 / (x + 3)
1/(x+1)+1/(x+7)=1/(x+5)+1/(x+3)
General score: (2x + 8) / [(x + 1) (x + 7)] = (2x + 8) / [(x + 5) (x + 3)]
We get: 2x + 8 = 0, or (x + 1) (x + 7) = (x + 5) (x + 3)
The former is x = - 4, and the latter is 7 = 15
After testing, x = - 4 is the root of the original equation

Simplification ratio 6 / 5:5 / 2 12.5:0.25 3.6:24

6/5:5/2
=12/10:25/10
=12：25
12.5:0.25
=50：1
3.6:24
=18：120
=3：20
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Given that the parabola passes through two points a (1,0), B (0, - 3), and the axis of symmetry is x = 2, the analytical formula of the parabola is obtained
Just the vertex!

Let the parabolic equation be y = ax ^ 2 + BX + C
=a(x^2+bx/a+b^2/4a^2)+c-4b^2/a
=a(x+b/2a)^2+c-4b^2/a
Then x = - B / 2A = 2, B = - 4A
Then the original equation is y = ax ^ 2-4ax + C
Because the point a (1,0) is substituted into the equation
a-4a+c=0 ->c=3a
So the original equation is: y = ax ^ 2-4ax + 3a
Substituting point B (0, - 3) into the equation, we get
3a=-3 a=-1
So the original equation is: y = - x ^ 2 + 4x-3

What is the sum of the quotient of 20 and 7 / 20 divided by 7 / 2?

7 / 20 divided by 7 / 2 = 7 / 20x2 / 7 = 1 / 10 = 0.1
20+0.1=20.1

The known set a = {x 2a-2}

A={x|2a-2＜x＜a}
B={x|1＜x＜2}
CRB = {x | x ≤ 1 or X ≥ 2}
Because a is really contained in CRB
The following is a classified discussion:
(1)
If a is an empty set, it naturally conforms to
So 2a-2 ≥ a
That is, a ≥ 2
(2)
If a is not an empty set
Then '2a-2 < a' and 'a ≤ 1 or 2a-2 ≥ 2'
So a ≤ 1
In conclusion, the value range of a is {a | a ≤ 1 or a ≥ 2}