Speed to give me 50 junior one's binary application questions plus answers urgent!

Speed to give me 50 junior one's binary application questions plus answers urgent!

There are 651 students in grade 2 and grade 3 of junior high school. The number of students in grade 2 is 10% more than that in grade 3, and the number of students in grade 2 and grade 3 is more than that in grade 3. 2 a factory has applied to the bank for two kinds of loans, a total of 2 million yuan, and 106000 yuan of interest should be paid every day

How to solve the system of linear inequalities of two variables
Additional examples
Otherwise I don't understand

1: If we can factorize it, we can first decompose it, then we can use the ordered axis root method to find the solutions of two inequalities, and then we can find their intersection
2: If you can't factorize, you can use the method of tracing. Using the method of tracing, you can find their respective solution sets through the image, and then find their intersection
Please refer to the first volume of senior high school mathematics textbook for detailed explanation

A system of quadratic inequalities of two variables
x + y ≤80
3x＋y≥150

3x＋y≥150
3x≥150-y
150-y≤3x
And X + y ≤ 80
Two formula addition
150+x≤80+3x
That is, X ≥ 35
x + y ≤80
3x+3y≤240
150≤3x+y
Two formula addition
150+3y≤240+y
y≤45

To solve the problem group of binary linear inequalities,
1. X = 4 is the solution of AX + 3 (X-7) / 2 - (x - one and three fifths) / 8____
4. The sum of integer solutions of | x-3 | ≤ 2 is______
The solution of inequality (| x | + x) (2-x) 1 is____________
8. Find the system of inequalities ① 2x-1 > 0
②x-2

A28 / 45 (28 / 45)
4.15 x>2
five
6. Maximum 9, minimum 0
7.x

The concept of function parity is not clear
If f (x + 1) is an even function, then we can get
A.f(x+1)=f(-x+1) B.f(x+1)=f[-(x+1)]
This is a bit messy. Do you need to take (x + 1) as a whole?

A. It's just that the independent variable x changes sign

It is proved that the function f (x) = - x2 + 3x + 1 is an increasing function at (negative infinity, 1) by definition

Let x1

A straight line L passes through a point P (- 6,0), and its intercept on the x-axis is equal to half of its intercept on the y-axis,

P is on the x-axis
The intercept of the x-axis is - 6
So the intercept on the y-axis is - 12
x/(-6)+y/(-12)=1
That is, 2x + y + 12 = 0

3 (X-7) = 8.7 calculated by a simple method
3 (X-7) = 8.7 calculated by a simple method

3（x-7)=8.7
x-7=2.9
x=9.9

Help... New junior high school mathematics summer homework
1. Xiao Ming and Xiao Lin are running in the morning on a 200 meter long circular track. They start in the same direction at the same time. Xiao Ming runs 125 meters per minute and Xiao Lin runs 75 meters per minute. When they first meet, how many meters did they run in total?
2. Xiao Ming and Xiao Lin are running in the morning on a 400 meter long circular track. They are walking from a to a at the same time. Xiao Ming runs 125 meters per minute and Xiao Lin runs 75 meters per minute. When they meet for the second time, how many meters did they run?
3. The passenger ship departs from port a to port B, and the cargo ship departs from port B to Port A. the two ships meet each other for 10 hours at the same time, and then continue to travel for 4 hours. At this time, the passenger ship is 250 kilometers away from port B, and the cargo ship is 350 kilometers away from Port A. how many kilometers are there between port a and port B?
4. A train with a total length of 120 meters passes the 880 meter long bridge at a speed of 50 km / h. how many seconds does it take for the train to get on the bridge and leave the bridge completely?
5. On Sunday, Xiao Ming and his grandfather went to climb the mountain together. The average speed up the mountain was 3 km / h, and the average speed down the mountain along the original road was 4.2 km / h. It took 2 hours more to go up the mountain than down the mountain. How many hours did it take to go up the mountain?

1. Xiao Ming and Xiao Lin are running in the morning on a 200 meter long circular track. They start in the same direction at the same time. Xiao Ming runs 125 meters per minute and Xiao Lin runs 75 meters per minute. When they first meet, how many meters did they run in total?
Suppose the meeting time is X minutes. Xiao Ming ran one more lap than Xiao Lin when he met
125x-75x=200
50x=200
x=4
When they met for the first time, Xiao Ming ran 125 × 4 = 500 meters and Xiao Lin ran 75 × 4 = 300 meters
2. Xiao Ming and Xiao Lin are running in the morning on a 400 meter long circular track. They are walking from a to a at the same time. Xiao Ming runs 125 meters per minute and Xiao Lin runs 75 meters per minute. When they meet for the second time, how many meters did they run?
Suppose the time of the second meeting is X minutes, and the two run 2 laps in the second meeting
125x+75x=400×2
200x=800
x=4
When they met for the second time, Xiao Ming ran 125 × 4 = 500 meters and Xiao Lin ran 75 × 4 = 300 meters
3. The passenger ship departs from port a to port B, and the cargo ship departs from port B to Port A. the two ships meet each other for 10 hours at the same time, and then continue to travel for 4 hours. At this time, the passenger ship is 250 kilometers away from port B, and the cargo ship is 350 kilometers away from Port A. how many kilometers are there between port a and port B?
Passenger and cargo ships travel the whole journey every hour
1 △ 10 = 1 / 10
Four hours after the meeting, we had the whole journey
1 / 10 × 4 = 2 / 5
The rest of the way
2 out of 1-5 = 3 out of 5
Three out of five are
250 + 350 = 600 km
The distance between port a and port B
600 △ 3 / 5 = 1000 km
4. A train with a total length of 120 meters passes the 880 meter long bridge at a speed of 50 km / h. how many seconds does it take for the train to get on the bridge and leave the bridge completely?
50 km / h = 9 / 125 m / S
The train went on the bridge from the beginning to the end
120 + 880 = 1000M
It takes a long time for the train to get on the bridge and leave the bridge completely
1000 △ 125 / 9 = 72 seconds
5. On Sunday, Xiao Ming and his grandfather went to climb the mountain together. The average speed up the mountain was 3 km / h, and the average speed down the mountain along the original road was 4.2 km / h. It took 2 hours more to go up the mountain than down the mountain. How many hours did it take to go up the mountain?
The distance up and down the mountain is x km
x/3-x/4.2=2
4.2x-3x=25.2
1.2x=25.2
x=21
It took X / 3 = 21 / 3 = 7 hours to get up the mountain

As shown in the figure, the line y = - 3 / 4x + 6 intersects the x-axis and y-axis at two points a and B respectively; the line y = 5 / 4x intersects with ab at point C, and the line passing through point a and parallel to Y-axis intersects with point D. point e starts from point a and moves to the left along the x-axis at a speed of 1 unit per second, The square pqmn is made to the right with PQ as the edge. Let the area of the overlapping part (shadow part) of the square pqmn and △ ACD be s (square unit), and the motion time of point e be t (seconds)
(1) find the coordinates of point C
(2) when 0 ＜ x ＜ 5, find the functional relationship between S and t
(3) find the maximum value of s in (2)
(4) when t > 0, the value range of T is directly written when the point (4,9 / 2) is inside the square pqmn

(1)C:(3 15/4)
(2)S=-2t＊t+10t 0