Ask a math problem in the first year of junior high school, and be in a hurry to add thanks 20

I don't understand the first question.

The second idea is:

Divide the number of people driving by the percentage to find the total number of people.

The number of angles in the center of the circle is the number of people walking divided by the total number of people multiplied by 360

1.Case 1, Main view: five squares stacked together (vertical column), Left view: 5 squares stacked together (vertical column).

Case 2, Main view: one on the left, 4 stacks on the right (vertical column), Left view: 4 squares stacked together (vertical column).

1) The number of people in the unit is x, x=32 40%=80 people.

The number of cyclists accounts for y, y=80*33%=26 people.

2) The number of people walking is z z = 80 - 32 - 26 - 8 = 14 people.

The proportion is c c = 14 80 * 100% = 17% and the number of angles in the center of the circle = 360 * 17% =

1. The first case: the main view is 12, and the left view is 22

The second case: main view 22, left view 12

2. (1) A total of 32 40%=80 (people).

There is a problem with the data of 80*33% of the cyclists.

It takes a lot of energy to type these words, 1

Type 1: Main view 12 Left view 22

The second type: main view 22 left view 12

2.(1) Solution: Let the unit have x people x = 32 40% = 80 people.

Solution: There are y people in the car y=80 times 30%=26 people.

2) Number of walkers: 80-32-26-8=14 (people) Proportion: 14 80 times 100% = 17%.

The degree of the central angle of the station: 360° times 17% =

First case: main view 12, left view 22

The second case: main view 22, left view 12

One 1: a + a + 40 +

2---1: ab-4 4/4 r squared = ab- r squared.

2: Will bring in 600-100

Meow: That's it.

1.Let the principal amount be x yuan, then.

x=16000

2. (1) If the unit price of the schoolbag is x and the walkman is y, then x+y=452

4x-y=8

From the above two equations, x=92 and y=360 can be calculated

That is, the unit price of the schoolbag is 92 yuan, and the walkman is 360 yuan.

2) In supermarket A: the total amount of the two goods is (92 + 360) * remaining yuan.

In B supermarket: buy 100 yuan back shopping coupon 30 yuan, if it is a shopping coupon with the amount of double, then buy a walkman 360 yuan, get a 90 yuan shopping coupon, now there is still 400-360 = 40 yuan, and then buy a shopping coupon to buy a school bag, you need more than 2 yuan in cash, then the last remaining 40-2 = 38

So both can go first, but in supermarket A it is more cost-effective and saves yuan.

If no matter how much you buy, as long as it exceeds 100, you will get a cash coupon of 30 yuan, then no matter how much you buy in 8 supermarkets, it will not be enough money to buy two goods. Only at A supermarket.

1.Let the principal amount be x yuan, then.

x=2.If the unit price of the schoolbag is x yuan, the unit price of the walkman is 4x-8, so 4x-8+x=452

x=148 The rest of yourself ponders slowly, and I believe you can quickly master this kind of questions.

== The time it emits from the light to the Earth is seconds.

Seconds distance divided by speed (speed of light).

Set four cars as X and eleven cars as Y.

60*70+60x+11y*10=500060x+110y=800

Set four cars as X and eleven cars as Y.

4x+11y=70

I believe that even if you are a first-year junior high school student, you can solve it

Solution: Set up 11 cars x cars, 11x < = 70

11x*10+(70-11x) 4*60<=5000-800 solution 50 11<=x<=6

x is an integer, so x can only be 5 or 6

When x=5, it cannot be exactly full of every car.

When x=6, the 4-seater car has (70-11*6) 4=1, so there is 1 4-seater car and 6 11-seater cars.

If the company rents a four-seater car x cars, then:

60x+（70-4x）*10≤800

x 5 because the problem needs 70-4x to be divisible by 11, so after calculating the range of x values, it needs to be brought into the calculation (i.e., x=1,2,3,4,5), so that when x=1, the problem requirements are satisfied.

Therefore, the company rented 1 four-seater car and 6 eleven cars.

Tickets: 70x60=4200

Fare: 5000-4200=800

There are x people in a four-seater car, and eleven people in a 70-x car.

60 * (x 4) + 10 * (70-x) ≤ or equal to 8005 x less than or equal to 100

x is less than or equal to 20

Therefore, the four-seater car is less than or equal to 5 cars.

5000-60*70=800

x+y=70 ①

60 (x 4) + 10 (y 11) 800 I haven't done math for a long time, and I don't know if it's right.

Solution: If a company rents a four-seater car x cars, it rents eleven cars 70 4x 11 cars, which is obtained by known conditions

60x＋[﹙70－4x﹚／11]×10＋60×70≤5000

The solution is x 13, but in order to meet the requirement of "the company's employees are exactly full of each car", then x=1 is taken, that is, the company rents 1 four-seater car and rents 11 cars 6 cars.

There are four cars x and eleven y cars.

4x+11y=70

60x+11*10y+60*70=5000 The rest is solved by itself.

Set up to rent 4 cars x cars.

60x+10*(70-4x): less than or equal to 5000-70*60

Note: I'm sorry, I don't use the computer to type less than or equal signs.

If there are x people in a four-seater car, then there are 70-x people in an eleven car.

x 4) multiply 60 + (70-x) multiply 10 + 70 times 60 less than or equal to 5000

The solution is less than or equal to x 20, and 70-x is greater than or equal to 50, so there are 5 cars for four seats and 5 cars for eleven cars.

If the company rents a four-seater car x cars, there are 11 people who take the car (70-4x).

This gives us 60x+(70-x)x10+60x<=5000, and (70-4x) 11=positive integer.

This gives us x=12

It took X hours for Xiao Ming to catch up with his mother.

Mom walked for an hour, which is 4 * 1 = 4 kilometers.

12x-4x=4

x = hours. Little Flower Dog and Little Ming set off at the same time, and they ran at the same time.

The little flower dog ran 16*km.

Set the little flower dog ran Y kilometers.

12-4）y/16=1*4

y=8 The little flower dog ran 8 kilometers.

Solution: Mom walked 4 kilometers in an hour.

Know the difference in distance, the difference in speed, and find the time.

The time it took for Xiao Ming to catch up with his mother was: 4 (12-4)=1 2 Because the time taken by Xiaohua Dog and Xiao Ming was the same, the speed of Xiaohua Dog was 16, so Xiaohua Dog walked a total of (1 2)*16=8

Let's say the little flower dog runs x kilometers.

Then after Xiao Ming caught up with his mother, the little flower dog ran for x 16 hours.

then there is; x/16*12=x/16*4+4

Solution x=8

The little flower dog ran a total of x kilometers.

x/16=4/(12-4)x=8