A few other application questions, can you help!! Gratitude, gratitude, gratitude!

Zhangjia 18 yuan.

Li family 24 yuan.

Wang's family 30 yuan.

11 kg left.

A total of 8 kg.

Hello! Solution: Let the velocity of A be x and the velocity of B y.

From the question, 5y=1500-5x(1).

50y=50x-1500（2）

then 15000-50x=50x-1500

100x=16500

Solution: x=165

y=155, A and B walked 825m and 775m respectively in 5 minutes.

Upstairs I didn't see clearly, it was "again" and walked for 45 minutes...

Method 1:

From the title, it can be seen that A travels 1500 meters more than B, and A travels 1500 (5 45) 30 (meters) more than B per minute

Let B travel x meters per minute, then A travels x 30 meters per minute 1500 5(x 30) 5x

Solution x 135

A line 135 30 165 (m) per minute

Method 2: From the problem, it can be seen that A travels 1500 meters more than B, and A travels 1500 (5 45) 30 (m) more than B per minute.

From "after 5 minutes, A has not yet reached the intersection, and the distance between the two people from the center of the intersection is equal", it can be seen that the distance traveled by B and the distance traveled by A is exactly 1500 meters, then the sum of the speed of A and B is 1500 5 300 (meters).

A walks (300 30) 2 165 (m) per minute and B walks (300 30) 2 135 (m) per minute

A velocity x m min.

B speed y meter minutes.

After 5 minutes, A walked 5x meters and B walked 5y meters.

At this point, A is 1500-5x meters away from the intersection because A is not at the crossroads, and B is 5y meters away, so B is 5y meters away from the intersection, and the first equation is 5y=1500-5x

After another 45 minutes, A walked 50x meters and B walked 50y meters if A had not yet reached the crossroads.

50y=1500-50x contradicts the first equation, so A must have walked through the crossroads, so the distance between A and the crossroads is 10x-1500

The second equation is 50y=50x-1500

The two equations are solved synchronously.

y=135 x=165 The mouth should be right. Then multiply by 5 and that's the answer.

"After 5 minutes, A has not walked to the intersection, and the distance between the two people from the center of the intersection is equal", then the distance A walked plus the distance traveled by B is exactly 1500 meters, so the speed of the two people is the same

1500 5 300 (m).

After another 45 minutes of walking", the two walked again:

300 45 13500 (m).

Because at this time, "the distance between the two people from the intersection is equal", that is to say, the distance from the intersection to A is the same as the distance from the intersection to B, that is, it is equivalent to twice the position of B from the intersection to the present, then the distance from the intersection to the current position of B is.

13500 2 6750 (m).

This distance B has walked a lot:

5 45 50 (min).

So, B's velocity is:

6750 50 135 (m).

Thus, the velocity at which the armor can be obtained is:

300 135 165 (m).

(1) Let the quantity of A x, the quantity of B y, x+y=40

15520 340x+420y 15630 solution 14y=24, x=16

y=25,x=15

2) Let u be about the profit of (x,y), i.e. u=(390-340)x+(500-420)y=50x+80y

If x+y=m, u=50m+30y=80m-30x=65m+30(y-x), it can be seen that when the y-x difference is the largest, that is, x=0, the profit is the largest.

[It is expected that the cost of the two toys will not be less than 15,630 yuan and not higher than 15,520 yuan] is not written down.

（1890-315）/（72+54）

A: After an hour, the distance between the two cars was 315 kilometers.

When not met: (1890 315) (72+54) hours).

After the encounter: (1890+315) (72+54) hours).

Let's say x hours later.

The equation can be obtained: 72x+54x = 1890-315 x= This is the first time (not encountered).

There is one more case.

72x+54x =1890+315

x= This is the second time (after the encounter).

After X hours, the two cars are 315km apart.

72*x+54*x+315=1890.Just solve x. Hour.

The number of apprentices processed is four-fifths of that of the master.

The number of processed by the master is five-quarters of that of the apprentice.

The master can process 60 4 5 = 75 (pieces) 75 15 = 1125 (pieces) per hour

A: There are 1125 parts in this batch.

60 times five-quarter times 15 equals 1125

Storybooks = 2820 (1+88%) = 1500 science books = 2820-1500 = 1320 books.

Good luck with your studies!

If you have any questions, please ask and be willing to answer them.

If you understand and solve your problem, please adopt it in time! o(∩_o

This is an obvious solution to a system of binary equations, and there are x story books and y science books in the library, which are derived from the title:

x+y=2880；x = simultaneous solution, y = 1320, x = 1500, so there are 1500 story books and 1320 science and technology books, respectively.

Total number of apples: 70 (40%-1 6) = 300

The number of apples in two baskets of C and D: 300 * (1-40% - 1 6) = 130

There are apples in the basket: 130 * 7 (6+7) = 70 (pcs).

Total number of apples in four baskets = 70 (40%-1 6) = 70 (2 5-1 6) = 70 (7 30) = 300.

The number of apples in two baskets = 300 (1-1 6-40%) = 300 * (13 30) = 130.

There are apples in the basket = 130 * 7 (6 + 7) = 130 * 7 13 = 70.

A:1 6;B: 2 5;Bing Ding Zhan:

1-1 6-2 5 13 30 The ratio of propylene to the number of propylene is 6:7C-Zhan:

13 30 * 6 13 1 5 Ding: 13 30 * 7 13 7 30

A is 70 less than B, 2 5-1 6 7 30 for a total of 70 (7 30) 300

Ding has: 300*7 30 70

Let A have x apples, then B has x + 70 apples, according to the ratio of the number of A and B is equal to the ratio of the proportion of the total number of A and B, the equation is calculated for x=50, that is, A 50, B 120, and then according to the proportion of A in the total number of 300, then the sum of C and D is (300-50-120) = 130, and finally 70 D can be obtained according to the ratio of the number of C and D.

The 29th is the day of the week, and the column formula should be the sum of the number plus a number, and then divide by 7, and see how many the remainder is, which is the day of the week. As for what number to add, it depends on the day of the week on which one of your days is, for example, if you are now on the 8th is Tuesday, (yesterday was the 8th, today is Wednesday) column formula 8 divided by 7, the remainder is 1, should be added 1 to calculate the calculation of this month, so this month is to add 1 to calculate the day of the week, the 29th also add 1, that is, 30 divided by 7, the remainder is 2, so it is Tuesday.

4，8，9，6。。。This is a group of four numbers, the 99th number is 99 divided by 4, 24, there is a surplus of 3, look at the remainder to know that it is the third number 9, the sum of 99 numbers is also calculated in groups, first count 24 groups, plus the extra (4 8 9 6) 24 4 8 9 669