What are the forms of some English abbreviations?

What are the forms of some English abbreviations?

The abbreviation of the United Nations is: UN
Abbreviation of the people's Republic of China: P.R.C
UNESCO is the abbreviation of the United Nations Educational, scientific and cultural organization

Abbreviations of common words in Mathematics
Real number, imaginary number, rational number, irrational number, natural number, positive integer, negative integer
Please know the prawn to answer

Real number
Imaginary number
Rational number
Irrational number
Natural number
Positive integer: positive integer
Negative integer

What's the abbreviation of the size classification of the model from big to small

From big to small, yes
PG>MG>RG>HG>FG>SD
It's basically arranged like this
But the volume of some large-scale bodies even after the Hg ratio is finished is larger than that of PG (because in the original work, it's a huge object of hundreds of meters, even if it's reduced by 1:144, it's larger than the 1:60 of the ordinary body of 20m)
In addition, FG has less domestic supply, which can be ignored

It is known that the quadratic equation of one variable 8x - (2m + 1) x + m + 7 = 0. According to the conditions, the value of M can be obtained, (1) two are reciprocal to each other, (2) two are opposite to each other

Let two of the equations be x1, x2. From the meaning of the question, we can get X1 + x2 = (2m + 1) / 8, X1 * x2 = (M-7) / 8 (1) two reciprocal numbers are X1 * x2 = (M-7) / 8 = 1, M = 15 (2) two reciprocal numbers are X1 + x2 = (2m + 1) / 8 = 0, M = - 1 / 2

Given that the real number a is not equal to 0, let the function y = ax + B / x-a (x is not equal to a), and prove that the image of this function is axisymmetric with respect to the line x = y

X is solved from y = ax + B / x-a (i.e. x is represented by Y), and x = ay + B / Y-A is obtained. By exchanging x with y, y = ax + B / x-a is also obtained. This shows that the inverse function of y = ax + B / x-a is itself. We know that the images of two functions which are inverse functions are symmetric with respect to the line y = x, while the inverse function of y = ax + B / x-a is itself, so the image of y = ax + B / x-a is axisymmetric with respect to the line y = X

The law of multiplicative distribution is a common tool. The calculation is 41.2 × 8.1 + 11 × 9.25 + 537 × 0.19

41.2×8.1+11×9.25+537×0.19，=333.72+101.75+102.03，=435.47+102.03，=537.5．

The inverse proportion function of junior high school mathematics‘‘‘
Known a (3,2) B (1,3)
The inverse scale function y = K / X intersects the line AB to find the value range of K
The more detailed the steps, the better``````

Solution: the analytic formula of the line AB is y = ax + B. by substituting the coordinates of a and B, we can get a = - 1 / 2, B = 7 / 2, y = - 1 / 2x + 7 / 2. The problem is transformed into the equation y = K / X and y = - 1 / 2x + 7 / 2. After the equation y = K / X is combined with y = - 1 / 2x + 7 / 2, there is a solution in the domain x ＞ 1 and ＜ 3

What's one sixth times three?

Negative half

1. Given the set a = {0,2,3,5,7}, then the number of all subsets of a is?
The answer is 32, but I think the empty set should also be counted? Please analyze, is it counted?

Two properties of empty set plus complete set
Five subsets of an element
Two element subsets 5 * 4 / 2 = 10
Three element subsets 10
Four elements and five subsets
All subsets = 2 + 5 + 10 + 10 + 5 = 32

The intersection of 3x-2y + 10 = 0 and 4x-3y + 2 = 0, and the line equation perpendicular to the line 2x-3y + 1 = 0 is?
What I want is! Not a word! Especially how to determine the slope! I know the answer, not a word!

The slope of 2x-3y + 1 = 0 is k = 2 / 3
The slope of the objective function is t, then t × k = - 1
That is t = - 3 / 2
The intersection of 3x-2y + 10 = 0 and 4x-3y + 2 = 0 is (- 26, - 34)
That is y + 34 = - 3 / 2 (x + 26)