For three consecutive even numbers, if the sum of squares of the first two numbers is less than 4, then the three numbers are

For three consecutive even numbers, if the sum of squares of the first two numbers is less than 4, then the three numbers are

Let the three even numbers be (X-2), x, (x + 2) respectively
（X-2）²+X²=X（X+2）-4
2X²-4X+4=X²+2X-4
X²-6X+8=0
（X-2）（X-4）=0
X1 = 2 (not suitable) x2 = 4
A: the three numbers are 2, 4 and 6 respectively

How many liters is a kilogram of gasoline equal to

Calculated by density of 0.74
One liter is 0.74 kg
So a kilogram of gasoline is estimated to be between 1.35 and 1.45 liters

Sixth grade first term mathematics paper (11) final review 4
A total of 83.2 yuan was paid last month. How many yuan should be collected according to each household's electricity consumption?
How much should the household pay for electricity consumption
Come on. By the way, the formula

It's too simple. 83.20 / "(40 + 38 + 29 + 53) = 0.52 yuan
Zhao family: 0.52 * 40=
Qian Jia: 0.52 * 38=
Sunjia 0.52 * 29
Li Jia 0.52 * 53=

Under the microscope, the cross section of a cell can be approximately seen as a circle, and its radius is 7.8 x 10 to the - 7th power M?
（π≈3.14）
Express it in the way of science and technology!

The square of 3.14 * (7.8 * 10 minus 7 power)
Original formula: = 1.910376 * 10 minus 12 power

Simple operation of 16-24 + 30-19

16-24+30-19
=(16+30)-(24+19)
=46-43
=3

How to expand mathematical thinking?
I listen carefully in class. I can understand all the problems in the textbook. I can also solve the math problems that are related to the examples, but those that are more difficult will not. Give me some suggestions,

Mrs.Wang Has brought us some silk scrapes
Mrs.Wang has brought some silk scraves—————— ————————
I am going to Hainan Island by plane this afternoon
I am___ _____ Hainan Island by plane this afternoon.(leave for

to us
leaving for

Explain solar and lunar eclipses

Solar eclipse is when the moon moves between the sun and the earth. If the three advantages are in a straight line, the moon will block the light from the sun to the earth, and the shadow behind the moon just falls on the earth. At this time, the phenomenon of solar eclipse occurs

The fifth grade mathematics classified review question bank

Mathematics mid-term test questions in grade five volume one
Class name score
1、 Fill in the blanks. (15 points)
1. 13.5 × 0.5 means ()
2. 13.5 △ 0.5 means ()
3. The area formula of parallelogram expressed by letters is ()
4. In the calculation of 0.756 △ 0.18, the divisor and divisor are expanded by the same multiple at the same time, and the divisor is converted into an integer, which is then () to () and then calculated
5. Fill in ＞, ＜ or =
19.7×2.6○19.7 36×0.5○36÷2 35.6○35.6÷0.25
6. 1200 square meters = () hectares 5.2 tons = () tons () kg
1.05 M = () cm
7. The bottom of a triangle is 3 decimeters, the height is 1.2 decimeters, and the area is ()
8. A and B buses drive from Renshou to Chengdu at the same time. Car a travels 60 kilometers per hour, while car B travels 65 kilometers per hour. After 1.5 hours, how many kilometers are there between the two buses? This problem can be solved first by (), and then by how many kilometers. The comprehensive formula is (), or by (), and then by how many kilometers
Second, judge. Mark "√" in () after the correct statement and "×" in () after the wrong statement (4 points)
1. The area of a triangle is half that of a parallelogram
·
·
2. 2.5 × 4.4 can be calculated as follows: 2.5 × 4 × 0.4
3、5.32727…… . can write 5.327
4. Two equal trapezoids can form a parallelogram
Add the serial number of the correct answer to ()
1. The correct and simple calculation method of 3.14 × 102 is ()
①3.41×100×2 ②3.14×100+2 ③3.14×100+3.14×2
2. Ten tons of coal were delivered to the canteen and planned to be burned for 40 days. Due to the improvement of the stove, 5 kg of coal was saved every day. How many days can this batch of coal be burned now? The correct formula is: ()
①40÷（40÷1－5） ②1000÷（1000 ÷40－5） ③1000÷（40－5）
3. The base of a triangle is expanded 5 times, the height is expanded 5 times, and the area is ()
① Expand 5 times, keep unchanged, expand 25 times
4、 Calculation. (48 points)
1. Write the number directly. (4 points)
1.5×4＝ 0.12×3＝ 0.49÷0.7＝ 6.4×0.2＋3.6×0.2＝
42÷0.6＝ 72.8÷0.8＝ 1.5÷30＝ 3×0.2×0.5＝
2. Calculation by simple method. (8 points)
99×2.45 5.6÷1.6
1.25×32＋215×9.76×0 9.85×2.3－8.85×2.3
3. Find the unknown number X. (6 points)
(keep one decimal place)
35.16－x＝27.36 1.5×x＝3.75 375.96÷x＝16
4. Calculated by the off formula. (12 points)
18.5＋4.1×7.2－9.5 10.48＋22.56÷4.7×5.4
18－(1.4－1.25×0.8) 0.8×[13－(3.12＋5.28)]
5. (12 points)
① What is the quotient of the sum of 8.4 and 1.6 divided by 4?
② What's the quotient of subtracting 6.9 from 10 and 24.8?
③ What's the product of 3.2 times 4 minus the quotient of 7.5 divided by 1.5?
Unit: cm
six
eight
ten
6. Calculate the shadow area. (6 points)
5、 Answer practical questions. (30 points)
1. Fang Fang's grandmother took 20 yuan to buy silver carp. It was 8.6 yuan per kilogram of silver carp. She bought 1.9 kilogram of silver carp. How much money was left? (10 points)
2. Students do good deeds. There are 42 students in class 4.1 and 42 students in class 4.2. Last term, class 4.1 did 336 good deeds, and class 4.2 did 210. Last term, how many more good deeds did class 4.1 do than class 4.2
3. There is a classroom which is 8 meters long and 6 meters wide. The floor is covered with tiles. Each tile is a parallelogram with a bottom of 4 decimeters and a height of 2.5 decimeters. How many tiles do you need to cover the floor of this classroom? (5 points)
4. A production team needs to process a batch of auto parts. The original plan is to process 400 parts per day and complete the task in 18 days. In fact, 450 parts per day are processed, so that the task can be completed several days ahead of the original plan? (5 points)
5. After school, Chen Yali comes home from school, and her mother comes to pick her up from home at the same time. Chen Yali walks 60 meters every minute, while her mother walks 80 meters every minute. They meet after 4 minutes. How many meters is Chen Yali's home from school? (4 points)
6. The distance between port a and port B is 1200 km. Ship a sails from port a to port B for 60 km per hour. 30 minutes after the departure of ship a, ship B sails from port B to port a for 70 km per hour. A few hours after the departure, ship B meets? (6 minutes)

Completion
1. Fill the empty bucket with 5 bowls of water or 6 cups of water. Now pour 2 bowls of water and 2 cups of water into the empty bucket, and the water level rises to () of the height of the empty bucket ()
Practical questions
1. It takes 12 days for a project to be completed by two engineering teams, team a and team B. now it takes four days for team a and team B to work together, and it takes 20 days for the rest to be completed by team a alone. If the rest of the project is done by team B alone, how many days will it take to complete it?
2. There are two groups in a workshop. The ratio of the first group to the second group is 5:3. If 14 people in the first group are transferred to the second group, the ratio of the first group to the second group is 1:2. How many people are there in the two groups?
3. A starts from place a to place B by bicycle at the speed of 12 km / h. After 2 hours, B starts from place a by motorcycle at the speed of 36 km / h to catch up with A. after a few hours, B can catch up with a?

Fill in the empty bucket with 5 bowls of water or 6 cups of water. Now pour 2 bowls of water and 2 cups of water into the empty bucket, and the water surface rises to (11 / 15) 1 / 5 × 2 + 1 / 6 × 2 = 11 / 15 of the height of the empty bucket