First, it is proved that AOC is 60 degrees, and then it is proved that the triangle OAC is an equilateral triangle, so all four sides are equal and all are diamonds.
The fourth question on page 67 of the fifth grade mathematics textbook of People's Education Press: the average annual precipitation in Tongxin County is X mm
8x+ 109=2325
8x+ 109- 109 = 2325- 109
8 x=22 16
8x \8 = 22 16 \8
x=277
People's education printing plate ninth grade first volume mathematics textbook answer P48 seventh problem exercise 22.3
7. The average yield of rice planted in Qingshan Village in 200 1 year was 7,200 kg/ha, and in 2003 it was 8,450 kg/ha, so as to seek the average annual growth rate of rice yield per ha.
Divide 7200 by the right to get x =112, and then turn it into a percentage.
That would be great.
How to do the problem on page 73 12 of the fifth grade mathematics textbook of People's Education Press 3x=x+ 100?
3x-x= 100
2x= 100
x=50
The ninth grade mathematics textbook of Hebei Education Press, Volume I: demo.educast/hbyc/right/chuzhong/chuzhong.htm.
How to solve the problem: 360 ÷ 10 = 24; 360 ÷22≈ 16 22'
Answer: When there are 15 gears, the included angle between the center lines of every two adjacent teeth is 24; With 22 teeth, the included angle is about16 22'.
If it is helpful to your study, please adopt it; If you have any questions, please ask.
The People's Education Press, the first volume of the fifth grade primary school mathematics textbook, page 129. Question 13 How to make a table tennis racket-badminton racket = 19.
Table tennis bat = 1.5 badminton bat
replace
1.5 badminton racket-badminton racket = 19
0.5 Badminton racket = 19
Badminton racket = 19×2=38
Table tennis bat = badminton bat+19=38+ 19=57.
Solution: If the price of table tennis racket is X, the price of badminton racket is x- 19.
x= 1.5(x- 19)
x= 1.5x-28.5
0.5x=28.5
x=57
The answer to the sixth question on page 105 of the second volume of the third grade mathematics textbook published by People's Education Press. Which of the following surveys adopts the general survey method and which adopts the sampling survey method? (1) Understand the service life of a batch of air conditioners; (2) the number of typos in the manuscript reviewed by the publishing house; (3) Investigate the fitness situation in the whole province. Answer (1) sampling survey (2) general survey (3) sampling survey.
How to cut it into several rectangles in the third question of Page 10 1 of the fifth grade mathematics textbook published by People's Education Press?
The tenth question on page 124 of the fifth-grade mathematics textbook published by People's Education Press, the beautiful peach blossom has lost its charm in spring.
Ah!