The formula of mathematical selling problem, distance problem, encounter problem and pursuit problem

The formula of mathematical selling problem, distance problem, encounter problem and pursuit problem

1. Number of copies × number of copies = total number of copies / number of copies = total number of copies / number of copies = number of copies
2. 1 times × times = several times △ 1 times = several times △ 1 times
3. Speed × time = distance △ speed = time distance △ time = speed
4. Unit price × quantity = total price / unit price = total quantity / quantity = unit price
5. Work efficiency × work time = total amount of work △ work efficiency = total amount of work time △ work time = work efficiency
6. Addend + addend = sum - one addend = another addend
7. Subtracted - subtracted = difference subtracted - difference = subtracted difference + subtracted = subtracted
8. Factor × factor = product △ one factor = another factor
9. Divisor / divisor = quotient divisor / quotient = divisor quotient × divisor = divisor
Primary school mathematics figure calculation formula
1. Square C perimeter s area a side perimeter perimeter = side length × 4 C = 4A area = side length × side length s = a × a
2. Cube V: Volume A: edge length surface area = edge length × edge length × 6 s surface = a × a × 6 volume = edge length × edge length × edge length v = a × a × a
3. Rectangle
C perimeter s area a side length
Perimeter = (length + width) × 2
C=2(a+b)
Area = length × width
S=ab
4. Cuboid
5: Volume s: Area A: length B: width H: height
(1) Surface area (L × W + L × H + W × h) × 2
S=2(ab+ah+bh)
(2) Volume = length × width × height
V=abh
5 triangles
S area a bottom h height
Area = bottom × height △ 2
s=ah÷2
Triangle height = area × 2 △ bottom
Triangle bottom = area × 2 △ height
6 parallelogram
S area a bottom h height
Area = bottom × height
s=ah
7 trapezoid
S area a upper bottom B lower bottom h height
Area = (upper bottom + lower bottom) × height △ 2
s=(a+b)× h÷2
8 round
S area C perimeter Π d = diameter r = radius
(1) Perimeter = diameter ×Π = 2 ×Π× radius
C=∏d=2∏r
(2) Area = radius × radius ×Π
9 cylinder
v: Volume H: height s; bottom area R: bottom radius C: bottom perimeter
(1) Side area = perimeter of bottom surface × height
(2) Surface area = side area + bottom area × 2
(3) Volume = bottom area × height
(4) Volume = side area △ 2 × radius
10 cone
v: Volume H: height s; bottom area R: bottom radius
Volume = bottom area × height △ 3
Total number △ total number of copies = average number
The formula of sum difference problem
(sum + difference) △ 2 = large number
(sum difference) △ 2 = decimal
The problem of sum times
Sum (multiple-1) = decimal
Decimals × multiples = large numbers
(or sum - decimal = large)
Differential multiple problem
Difference (multiple-1) = decimal
Decimals × multiples = large numbers
(or decimal + difference = large)
The problem of tree planting
1. The tree planting problem on non closed lines can be divided into the following three cases
(1) if both ends of the line are not closed, then:
Number of plants = number of segments + 1 = total length △ plant spacing-1
Total length = plant spacing × (number of plants - 1)
Plant spacing = total length (number of plants - 1)
(2) if trees are to be planted at one end of the non closed line and not at the other end, then:
Number of plants = number of segments = total length △ plant spacing
Total length = plant spacing × number of plants
Plant spacing = total length △ number of plants
(3) if trees are not planted at both ends of the non closed line, then:
Number of plants = number of segments-1 = total length △ spacing-1
Total length = plant spacing × (number of plants + 1)
Plant spacing = total length (number of plants + 1)
2. The quantitative relationship of tree planting on closed lines is as follows
Number of plants = number of segments = total length △ plant spacing
Total length × plant spacing
Plant spacing = total length △ number of plants
Profit and loss
(profit + loss) △ the difference between the two distributions = the number of shares participating in the distribution
(big profit - small profit) △ the difference between the two distributions = the number of shares participating in the distribution
(big loss - small loss) △ the difference between the two distributions = the number of shares participating in the distribution
Encounter problem
Encounter distance = speed and X encounter time
Encounter time = encounter distance △ speed and
Speed sum = encounter distance △ encounter time
Follow up questions
Pursuit distance = speed difference × pursuit time
Distance and pursuit time
Speed difference = pursuit distance △ pursuit time
Flow problem
Downstream velocity = hydrostatic velocity + water velocity
Countercurrent velocity = still water velocity - water velocity
Hydrostatic velocity = (downstream velocity + countercurrent velocity) △ 2
Water flow velocity = (downstream velocity countercurrent velocity) △ 2
Concentration problem
Weight of solute + weight of solvent = weight of solution
Weight of solute / weight of solution × 100% = concentration
Weight of solution x concentration of solute
Weight of solute △ concentration = weight of solution
Profit and discount
Profit = selling price cost
Profit margin = profit / cost × 100% = (selling price / cost-1) × 100%
Up and down amount = principal × up and down percentage
Discount = actual selling price △ original selling price × 100% (discount < 1)
Interest = principal × interest rate × time
After tax interest = principal × interest rate × time × (1-20%)
Length Conversion
1 km = 1 000 m 1 m = 10 decimeters
1 decimeter = 10 cm 1 meter = 100 cm
1 cm = 10 mm
Area Conversion
1 sq km = 100 ha
1 ha = 10000 M2
1 square meter = 100 square decimeter
1 square decimeter = 100 square centimeter
1 sq cm = 100 sq mm
Volume (volume) product unit conversion
1 cubic meter = 1000 cubic decimeter
1 cubic decimeter = 1000 cubic centimeter
1 cubic decimeter = 1 liter
1 cc = 1 ml
1 cubic meter = 1000 liters
Conversion of weight unit
1 ton = 1000 kg
1kg = 1000g
1kg = 1kg
Conversion of RMB units
1 yuan = 10 Jiao
1 jiao = 10 points
1 yuan = 100 points
time conversion
1 century = 100 years 1 year = December
Big month (31 days): January, March, may, July, August, October, December
Small month (30 days): April, June, September and November
The average year is 28 days in February and leap year is 29 days in February
There are 365 days in a normal year and 366 days in a leap year
1 day = 24 hours, 1 hour = 60 minutes
1 minute = 60 seconds 1 hour = 3600 seconds
Calculation formula of perimeter area volume of primary school mathematics geometry
1. Circumference of rectangle = (length + width) × 2 C = (a + b) × 2
2. Perimeter of square = side length × 4 C = 4A
3. Area of rectangle = length × width s = ab
4. Area of square = side length × side length s = A.A = a
5. Area of triangle = bottom × height △ 2 s = ah △ 2
6. Area of parallelogram = base × height s = ah
7. Area of trapezoid = (upper bottom + lower bottom) × height △ 2 s = (a + b) H △ 2
8. Diameter = radius × 2 D = 2R radius = diameter △ 2 r = D △ 2
9. Circumference of circle = circumference × diameter = circumference × radius × 2 C = π d = 2 π R
10. Area of circle = circumference × radius × radius
Selling problem: money paid = accounts payable + money recovered; or current selling price = cost price * (1 + profit)
Distance problem: distance = speed * time; encounter problem: distance = speed and * encounter time
Pursuit problem: distance difference = speed difference * pursuit time
The two brothers walked from 840 meters away from each other. A walked 65 meters per minute, B 75 meters per minute. B took a dog and set out together. The dog ran to a at the speed of 150 meters per minute. After meeting a, he ran to B, and after meeting B, he ran to A. until a and B met, the dog stopped. How many meters did the dog run?
When it comes to selling, consider the price. Don't miscalculate. When it comes to itinerary, consider whether the distance is the same or the time is the same? Or the same speed? Generally speaking, I use the itinerary to answer the questions. I will answer the specific questions, but the formula is not easy to say
For junior high school factorization exercises, the best answer
100 questions
ax+ay=a(x+y)
If the left side of the equation 2x & # 178; - (M-3) x + 2 = 0 about X can be written as a complete square expression, then M is a value
Definition of complete square formula: for an integral a with several simple variables, if there is another real coefficient integral B such that a = B ^ 2, then a is said to be a complete square formula
When B & # 178; - 4ac = 0, it can be written as a complete square
(M-3) &# 178; - 4 * 2 * 2 = M & # 178; - 6m-7 = 0, M = - 1, or M = 7
The formula of encounter problem
Catch up: (a speed - B speed) * time = distance
Project: (efficiency a + efficiency b) * time = total project
Encounter: (speed a + speed b) * time = distance
Factoring exercises and answers
What's the problem?
If the left side of the equation 4x - (m-2) x + 1 = 0 is a complete square, then the value of M is ()
6 or - 2
Six
7. Answer: 4x = m-2) - 1
On the formula of meeting problem
Total distance = speed and * encounter time
The problem of factorization
（a²+7a+2）² －16
2a³b－4a²b²＋2ab³
a² －b² －c² －2bc
m² －5m－14
2x² －4x＋2
（x+2)(x+4)+x² －4
Thanks. The faster, the better. I have to take my homework to class at five o'clock. It's all my fault that I'm incompetent and the teacher can't understand everything
Another question
x(x－1)－(x² －y）= －3
Find the value of X & sup2; + Y & sup2; - 2XY
（a2+7a+2）2 －16=(a2+7a+2+4)*(a2+7a+2-4)=(a2+7a+6)*(a2+7a-2)=(a+1)(a+6)(a2+7a-2)
2a3b－4a2b2＋2ab3=2ab*(a2-2ab+b2)=2ab*(a-b)2
a2 －b2 －c2 －2bc=a2-(b2 + c2 + 2bc)=a2-(b+c)2=(a-b-c)*(a+b+c)
M2-5m-14 = (M-7) * (M + 2) (only one step, no process)
2x2 －4x＋2=2（x2 －2x＋1）=2(x-1)2
（x+2)(x+4)+x2 －4=（x+2)(x+4)+(x2 －4)=（x+2)(x+4)+(x-2)(x+2)=(x+2)(x+4+x-2)=2(x+2)(x+1)
The topics are very simple, as long as you listen carefully, you will definitely do it. Come on~
When the equation x2-4x = 5 is solved by the collocation method, both sides of the equation are added at the same time______ So that the left side of the equation forms a complete square
∵ x2-4x = 5, ∵ x2-4x + 4 = 5 + 4, ∵ when the equation x2-4x = 5 is solved by the collocation method, 4 is added to both sides of the equation at the same time, so that the left side of the equation forms a complete square
Who can tell me the formula of encounter problem
The fifth grade of primary school
Encounter time = total distance △ speed and
A's distance = A's speed × encounter time