Help me solve a few 6th grade math problems and write down the process of solving them

Question 1: This book consists of x pages.

From Xiao Ling's words, you can get 2 5x=3 4x-28

The calculation yields x=80

Question 2. Set the purchase price to x and purchase y pairs.

According to the question, xy=800 (purchase cost).

Sell it for 80 yuan to get 80 yuan.

According to the title, 80y+64=800

Solution: y=

Question 1: By saying that the ratio of the number of pages seen to the number of pages left is 2:3, it can be seen that the number of pages that have been read is 2 5 of the total number of pages

2 Question: If it is only sold for 80 yuan, the difference of 64 yuan is enough. What does that mean?

What happens if you only sell?

1. Solution: This storybook has a total of x pages. Rule.

3/4x-2/（2+3）x=28

Solve the equation to obtain: x=80 (page).

A: This storybook is 80 pages long.

2. Solution: Set the purchase price of each pair of slippers to be X yuan, and purchase a total of Y pairs.

According to the title, it can be obtained:

yx（1+15%)=120

80y+64=xy

Solve the system of equations to get: x=

1.This storybook is set up to be x pages long. Rule.

3/4x-2/（2+3）x=28

x=80 (page).

A: This storybook is 80 pages long.

120 15% = 800 (double).

80*800=64000 (yuan).

64000 + 64 = 64064 (yuan).

64064 800 = yuan).

A: The purchase price of each pair of slippers is RMB.

1) Solution: Let Xiaojie read the number of pages x, the number of remaining pages is y, and the total number of pages of the storybook is x+y according to the title: x y=2 3

3/4(x+y)-y=28

Solution: x=32; y=48

The total number of pages is x+y=80 pages.

1.This storybook is set up to be x pages long. Rule.

3/4x-2/5x=28

x=80 (page).

A: (omitted).

Establish. The distance between A and B is x kilometers.

x 50+x bridge lease 40=9

4x+5x/200=9

9x=1800

x = 200 "km" macro.

Let's go into more detail.

1.Let the total length be s, then the velocity of A is s 16 and B is s 24

It is known that the walk has been 8 hours in advance, and there is still a distance of s-s 24*8=2*s 3 that has not been walked.

The two met after another t hour, and the title can be derived:

t*(s/16+s/24)=2*s/3

t*(s/16)+

t=32 5,s=108

So A's speed is 27 4 and B's speed is 9 2 per hour

2.From the title, let the speed of A be x, the speed of B is y, and the whole process is s: s 2+15=

s/2-15)/x=

It can be concluded that s=, x=5

Because, so y=

3.Let A have a speed of x and B have a speed of y, and after 2 hours, they are 80 km apart, and then they are 50 km away for 1 hour and 30 minutes, and they meet each other for another t hour.

2+xt+yt=50

t=,x=12,y=8

4.Let the total length be s, and let the passenger car travel for an hour and then travel for t hours, then: s=

s=52*t+122

It can be concluded that s=330

5.Set B departed for 5 minutes and traveled for another T minutes.

Then: 120*t+1200=5*100+100*t+1700 so t=50, so the distance between the two places is 120*50+1200=72006Let the full length be s, then it can be obtained from the title.

s 42=(36+36+s) 45-7 5, so s=126

1.Set up black sheep x only.

x+5/7x=120

Get 12 7x=120

x = 70 black sheep 70 white sheep 50.

2.Let's be last year's x

x=4/3x≈133％

Tired... Choose me...

Solution: If there are x black sheep, then there are (5 7) x white sheep.

x+(5 7)x=120, the solution is x=70

A: There are 70 black sheep and 50 white sheep.

Solution: This year, we have produced (10,000 pieces.

1 120 divided by (5+7)=10 black sheep 10*5=50 white sheep 10*7=70.

2. This year's percentage is divided by 133%.

1135 pear trees.

540+135 675 peach trees.

2 Xiaohua gave his own stamps to Xiao Ming, and the number of stamps for the two people was the same, so Xiao Hua turned out to have more than Xiao Ming's 25 Xiao Ming's 75

70 (1+Zhang Xiaohua.)

70-40 30 Xiao Ming.