The position of the corresponding point of the real number AB on the number axis is known, a > 0, B

a>0,bb,b-a

There are 58 students in class 6 (1) of Yingbin primary school. Can two or more of them celebrate their birthdays in the same week?
If you want a formula, you have to have a reason!

It is drawer principle! Analysis: because a year is basically 365 days, a week is a week, a total of 52 weeks more than one day, counted as 53 weeks, and the class has 58 students, so of course, there are 2 or more people in the same week birthday. 365 △ 7 = 52 (weeks). 1 (days) ≈ 53 weeks, 58 △ 53 = 1.3 (people), so there are 3 people in the same star

A-1 part of a △ a square - 1 part of a square - 1 part of a square - 1 part of A-1 part of A-1 part of a calculation, simplify (a square - AB part of B + b square - AB part of a) × a + B part of ab

Original formula = A / (A-1) ×
There is a little problem with this topic
(a square AB Part B + b square AB part a) × a + B part ab
=[b/a(a-b)-a/b(a-b)]×ab/(a+b)
=(b²-a²)/ab(a-b)×ab/(a+b)
=-(a+b)(a-b)/(a+b)(a-b)
=-1

(1) The car runs 100 kilometers per hour, 4 hours from a to B. the truck runs 80 kilometers per hour, how many hours can it reach?
(2) Xiaoqiang and Xiaojie compete to roll the hoop. Xiaoqiang's hoop diameter is 42cm, rolling forward 16 times per minute. Xiaojie's hoop diameter is only 35cm. If you want to win Xiaoqiang, how many laps should Xiaojie's hoop roll at least per minute?
(3) If you use a square carpet to lay the floor, if you use a carpet with a side length of 4 DM, you need 500 pieces. If you use a carpet with a side length of 6 DM to lay the floor, how many pieces of carpet do you need?
Do it with the scale equation
Format:
() is proportional to ()
Design

1) The speed is inversely proportional to the time. Suppose that the freight car reaches in X hours. 100 * 4 = 80xx = 5 A: it can reach in 5 hours. 2) the circumference is inversely proportional to the number of laps. Suppose Xiaojie rolls at least x laps per minute. 42 π * 16 = 35 πxx = 19.2 ≈ 20 A: Xiaojie's iron ring should roll at least 20 laps per minute. 3) the side length is inversely proportional to the number of blocks

Given the equations a + 2b-17c = 0, 3b-2a-15c = 0, where C ≠ 0, find the value of (a-b + C) / (a + B-C)

A + 2b-17c = 0 ① 3b-2a-15c = 0 ② from ①: a = 17c-2b 3 substituting 3 into ②: 3a-2 (17c-2b) - 15C = 03b-34c + 4b-15c = 07b-49c = 0b = 7C substituting B = 7C into ①: a = 17c-14ca = 3C substituting B = 7C, a = 3C substituting A-B + C / A + B-C: A-B + C / A + B-C = 3c-7c + C / 3C + 7C = - 3 / 9 = -

15. Vehicles a and B leave a and B respectively. Vehicle a travels 50 kilometers per hour and vehicle B 40 kilometers per hour. Vehicle a arrives one hour earlier than vehicle B

An hour earlier is an extra hour's journey at the same time
The extra distance is 1 * 40 = 40 km
The total time is 40 / (50-40) = 4
The distance between the two places is 4 * 50 = 200 km

Solve the following equation: 23-5x = 2x + 9

23-5X=2X+9
7X=14
X=2

The distance between a and B is 96 kilometers. The express and local trains run from each other. They meet in four fifths of an hour. Their speed ratio is 3:2

96 △ 4 / 5 = 120 (km)
120 ÷ (3 + 2) × 3 = 72 (km) - Express
120 ÷ (3 + 2) × 2 = 48 (km) --- slow train

Fractions with denominator of 10.100.1000 etc. can be easily rewritten into decimals. Please rewrite the following fractions into decimals
3 / 4 = -
12 out of 25 = -
1 out of 8 = -
1 / 2 = 10 / 5 = 0.5

2 / 5 = 0.4
3 / 4 = 0.75
12 out of 25 = 0.48
1 / 8 = 0.125

A. B is 80km away. A and B start from a to B. one hour after a starts, B catches up with a speed 1.5 times that of A. when B catches up with B, a arrives 20 minutes ahead of B. what's the speed of a and B?

Suppose the speed of a is XKM / h, then the speed of B is 1.5xkm/h. According to the meaning of the question, we can get: 80x − 801.5x = 1 − 2060 solution: x = 40 test: substitute x = 40 into 3x ≠ 0, so x = 40 is the solution of the original equation, so the speed of B is: 1.5x = 60 (km / h) answer: the speed of a and B is 40km / h and 60km / h respectively

The position of the corresponding point of the real number AB on the number axis is known, a > 0, B