A mathematics problem in grade two, solve it! To build a dam, the Red Star brigade needs to be completed within the specified date. If it is done by team a, it will be completed as scheduled. If it is done by team B, it will be more than 3 days after the specified date. Now, after 2 days of cooperation between team a and team B, the rest of the project will be done by team B alone, just within the specified date. It will take several days for team a to do it alone

It takes X days to set up a team to do it alone,
2/x+x/(x+3)=1
x=6
A: it takes 6 days for team a to do it alone

The meaning of common letters in microeconomics

List of symbols in macro and micro economics 1 (micro part)
Chapters appearing
Symbolic representation
English meaning
Chinese meaning
Notes on mathematical calculation
Chapter 2
D demand
S supply
P price 2.1
Q quantity 2.2
Ed price elasticity of demand
2．3
EM income elasticity of demand
M money revenue
EAB cross price elasticity of demand
2．4
Es price elasticity of supply
2．5
Chapter 3 Tu total utility Tu = f (q)
Mu marginal utility
Mrsxy marginal rate of substitution
Chapter 4
Chapter 4 L labor
K capital capital
TC total cost TC = f (q) 4.1
AC average cost
4．2
MC marginal cost
4．3
FC fixed cost FC = constant 4.4
VC variable cost VC = f (q) 4.5
TR total revenue tr = f (q) = P × Q
Ar average revenue
Mr marginal revenue
π profit π = tr-tc 4.6
TP total product TP = f (L) 4.7
Average production of AP average product
4．8
MP marginal product
4．8
Mrtslk marginal rate of technical substitution
STC short run total cost STC = f (q) = FC + VC
STFC (FC) short run total fixed cost STFC = constant
STVC
(VC) short run total variable cost STVC = f (q)
SAC
(ATC) short run average cost
SAFC
(AFC) short run average fixed cost
SAVC
(AVC) short run average variable cost
SMC short run marginal cost
LTC long run total cost LTC = f (q)
Lac long run average cost
LMC long run marginal cost
Chapter 6 VMP value of marginal product
MRP marginal revenue product
W wage salary
Note:
2.1 the prices of different commodities or factors are represented by different subscripts, such as X, y, l and K
2.2 sometimes it is demand quantity QD, sometimes it is supply quantity QS, sometimes it means output or other quantity
2.3 sometimes referred to as EP, sometimes referred to as demand elasticity or price elasticity
2.4 sometimes referred to as cross elasticity
2.5 is sometimes referred to as elasticity of supply
4.1 it may be short-term total cost, long-term total cost and sometimes C
4.2 it may be short-term average cost or long-term average cost
4.3 it may be either short-term marginal cost or long-term marginal cost
4.4 is also the short-term total constant cost, also known as fixed cost
4.5 is the total short-term variable cost, also known as variable cost
4.6 is also called economic profit, or excess profit
4.7 is sometimes expressed as Q
4.8 if variable inputs are other elements, different subscripts can be added
List of symbols in macro and micro economics 2 (macro part)
The chapter symbols appear to indicate the English meaning and the Chinese meaning of mathematical calculation notes
Chapter 9 GDP gross domestic product
C consumption C = f (y) = C0 + by 9.1
I investment
G government payment
Nx net export NX = x-m
X export
M import
NDP net domestic product
Ni national income
PI personal income
PDI personal disposable income
GNP gross national product
Chapter 10 y total 10.1
APC average propensity to consumption
MPC marginal propensity to consumption
ten point two
S save 10.3
APS average propensity to save
MPs marginal propensity to save
ten point four
Ad aggregate demand ad = C + I + G + X
As aggregate supply as = C + S + T + M
T tax
K multiplier
ten point five
Chapter 11 MEC marginal efficiency of capital
L demand for money L = L1 (y) + L2 (R)
R rate
M money supply
Chapter 13 CPI consumer price index
Chapter 14 kg government expenditure multiplier
fourteen point one
KTR transfer payment multiplier 14.2
TR transfer payment
KT tax multiplier
KB balanced budget multiplier
Chapter 15 MH money base MH = M0 + re 15.1
Ke deposit expansion multiplier
fifteen point two
Km money multiplier
fifteen point three
Chapter 16 m import M = M0 + my
KX foreign trade multiplier
Chapter 17 rate of growth
seventeen point one
Real growth rate of GT
GW anticipated rate of growth
GN nature rate of growth
Note:
9.1 where C0 is spontaneous consumption and CY is induced consumption
9.2 is different from GDP in that the former is based on the nationality of the producer, while the latter is based on the place of production
10.1 is often used to express national income, but also total demand and total supply
10.2 in the above consumption function, the marginal propensity to consume is B
10.3 for two sector economy, y = C + s
10.4 for two sector economy, MPC + MPs = 1, APC + APS = 1
10.5 the multiplier here refers to the investment multiplier
14.1 this is still the multiplier for the two sector economy (excluding tax)
14.2 this is the multiplier for the three sector economy
15.1 M0 - cash in circulation; re - deposit reserve
15.2 D - derivative deposit; Mr - original deposit; RD - statutory reserve ratio
3 M1 - money supply; MH - base money
1 s - saving rate, s = s / Y; J - capital output ratio, j = K / y
Due to the rush of time, if there is any omission or error, I hope you can correct it in time. Thank you very much

How do you read smoke

When I put it in front, it should be changed to y, so Ian = Yan (this is in Chinese), English pronounced "Ian"

Two circle chord length formula

The linear equation of the common string is obtained by subtracting the two circular equations
Then arbitrarily use one of the circles and straight lines to find the chord length
The distance between the center of a circle and a straight line is obtained by using the distance between a point and a straight line

What is the formula for calculating attendance rate, passing rate, germination rate, flour yield, salt content (sugar content) and survival rate?

Attendance rate = attendance number / total number × 100%, passing rate = passing number / total number × 100%,
Germination rate = germination number / total number × 100%, flour yield = flour yield / rice yield × 100%,
Salt content = salt content / total amount of salt and water × 100%, sugar content = sugar content / total amount of sugar water × 100%,
Survival rate = survival number / total planting number × 100%

Exponential and logarithmic equations
Given that x 1 is the root of the equation x + lgx = 4 and x 2 is the root of the equation x + 10 ^ x = 4, find the value of x 1 + x 2

Lgx = 4-x 10 ^ x = 4-x (the root here can be regarded as the intersection of two images)
10 ^ X and LG10 are inverse functions and symmetric with respect to y = X
And because y = x is perpendicular to y = 4-x
So X1 and X2 are symmetric with respect to y = X
X = 2 of simultaneous y = x and y = 4-x
Then x2 + x2 = 2 * 2 = 4

A cube with a side length of 10cm. Dig out a small cube from the middle. The side length of the small cube is 2cm. What is the surface area of the large cube now

1000 square centimeters

There are 100 oranges in 10 bags, 10 in each bag. Among them, 9 oranges in each bag weigh 50g, and each one in the other bag weighs 45g. These 10 bags of oranges are mixed together and can only be weighed once by scales. Can you find out which bag each is 45g? Please write down your method

First, number ten bags, 1, 2, 3... 10, then take one from the first, take two from the second, and so on, take 10 from the tenth. If all the bags are 50g, the total weight should be 50 × (1 + 2 + 3 +. + 10) = 2750g
Now weigh it, then subtract the total weight from 2750 and divide it by 50-45 = 5. The number is 45 grams

Given that the domain of function f (x) is x ∈ [- 1 / 2,1 / 2], find the domain of function y = f (AX) + F (x / a), (a > 1)

There is - 1 / 2 in F (AX)

Simplify f (x) = 2 (cosx) ^ 2 + 2 SiN x cos x + 1
Sorry, the wrong number is f (x) = 2 (cosx) ^ 2 + 2 * radical 3 SiN x cos x + 1

F(X)=2（COSX）^2+2*√3 sin x cos x+1=-[1-2（COSX）^2]+√3 sin (2x)+2=√3 sin (2x)-[1-2（COSX）^2]+2=√3 sin (2x)-cos(2x)+2=2[sin (2x)*(√3/2) -cos(2x)*(1/2)]+2=2sin(2X-π/6)+2