Elementary two's one variable one degree inequality application question A rectangular plot is 8 meters wide and less than 50 meters in circumference, with an area of at least 120 meters square Find the value range of the length of the rectangle

Elementary two's one variable one degree inequality application question A rectangular plot is 8 meters wide and less than 50 meters in circumference, with an area of at least 120 meters square Find the value range of the length of the rectangle

Let the length of the rectangle be X
8x≥120
8 + x ＜50\2
Solution: 15 ≤ x < 17

How to find the slope in high school mathematics?

The slope, also known as "angle coefficient", indicates the inclination of a line relative to the abscissa axis. The tangent of the angle between a line and the positive half axis of the abscissa axis of a plane rectangular coordinate system is the slope of the line relative to the coordinate system

If a, B, C ∈ R +, and ab + BC + Ca = 1, it is proved that a + B + C ≤ 1 / 3ABC
If the left side of the inequality is once and the right side is - 3 times, which can be adjusted by ab + BC + Ca = 1, then it can be
A + B + C ≤ (AB + BC + Ca) ^ 2 / 3ABC, but then, I can't melt it

Let y = 1 / (3ABC) - (a + B + C) replace 1 with ab + BC + AC to get y = 1 / (3a) + 1 / (3b) + 1 / (3C) - (a + B + C), then replace 1 with ab + BC + AC to get y = (1 / 3) * (BC / A + AC / B + AB / C - (a + B + C)) into fractional form to get y = (1 / (3ABC)) * (b2c2 + a2c2 + a2b2-a2bc-b2ac-c2ab) 2 is flat

The calculation formula of δ in CPK
May I ask which netizen can explain why the calculation formula in CPK is divided by n-1 instead of n

This is a very good question. Unfortunately, the answers given by friends on the second floor are too wide and scattered, but they do not simply hit the root of the question. It is estimated that it is the reason for online copy. Obviously, if we subtract 1 from the denominator (that is, divide by n-1), the standard deviation will be greater than the actual size. So why do we do this? This is mainly because

0.9 - (4 / 5-3x + 0.2x) = 3 / 2-x

0.9-(4/5-3x+0.2x)=3/2-x
0.9-0.8+3x -0.2x = 1.5-x
3.8x = 1.4
x = 7/19

The perimeter of a rectangle is 64 meters. If the length is reduced by 1 / 10, the width is increased by 1 / 6, and the perimeter is unchanged, the area of the rectangle is calculated
But I don't want to see the equation. I'll give him 60 points, which is 20 + 20,
If you answer well, there are still a few questions to ask you. You can get more points. You don't need to use the equation. You can use the calculation test and the head guarantee. The good one is 30 + 20. The best one is the simplest person. The formula gives you 40 + 20. Don't copy it from the Internet. I've seen it all. It's very annoying. It's also annoying to have arithmetic solutions,

Length + width = 64 △ 2 = 32 m
Length: width = 1 / 6:1 / 10 = 10:6 = 5:3
So length = 32 △ 5 + 3 × 5 = 20m
Width = 32-20 = 12m
Comprehensive formula:
Length = 32 ÷ (1 / 6 + 1 / 10) × 1 / 6 = 20m
Width = 32-20 = 12m
Area = 20 × 12 = 240 square meters
Have a good time

Answer a math problem! Wait online for 10 minutes
The following is the number of pulse times of class 5 (1) students in one minute after the 800m race
158、157、138、164、143、155、162、165、148
168、158、150、152、158、153、153、165、158
156、136、132、158、155、150、152、154、142
158、159、147、163、145、164、145、157、165
What is the average, median and mode of this set of data?
How many students have pulse times of 155 times and above? How many students have pulse times of 155 times and below?
Which data do you think is more suitable to represent the pulse frequency of class 5 (1) students after 800m race?
[urgent]!

Hello!
(1) Mean: 155; median: 155; mode: 158
(2) 20; 16
(3) Mode
[I hope I can help you]
[hope to adopt ~ ~]

Solution equation: 1-1 / 3x = 2 (1-3 / 8x)

1-1/3x=1-3/4x
X1 = radical 3 / 2 + 1.5 x2 = 1.5-radical 3 / 2

There are two squares. The side length of the big square is one centimeter more than two times that of the small square, and the circumference difference between them is 24 centimeters. How about the area of the two squares?

Let the side length of a small square be a centimeter, then the side length of a large square be (2a + 1) centimeter, (2a + 1) × 4-4a = 24, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 8A + 4-4a = 24, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & 4A + 4 = 24, & nbsp; & nbsp; & nbsp; & nbsp

In physics, the ratio of the distance an object travels to the time it takes is called the distance of an object____ It means how fast an object moves in the process

In physics, the ratio of the distance an object passes to the time it takes is called the speed of the object, which indicates the speed of the object in the process