X X

- = - -36

36 25

How much is x? Do the math yourself.

1. The school plans to plant trees around the campus. The total difference between planting trees every 30 meters and every 25 meters is 36. Question 1: What is the perimeter of the campus? Question 2: How many trees should be planted every 25 meters?

1. Let the perimeter of the school be x meters.

X X

- = - -36

30 25

X = 5400 meters

A: ...

Planting y tree

5400/25=2 16 trees

A: ...

2. Xiaoqing took 138 photos during the holiday and put them in the photo album. Put the same number of photos on each page, and there are only 2 photos on the last page. If each page can't be less than two pages or more than ten pages, how many pages does this album have? How many photos do you put on each page?

1 Let * * have x.

( 138-2)

2 & lt———& gt； 10

X

136/3=45.33333333333333333……

136/4=34

136/5=27.2

136/6=22.666666666666666666666……

136/7= 19.42857 1……

136/8= 17

136/9= 15. 1 1 1 1 1 1 1 1 1 1 1 1……

Because photos are integers, the possible number of pages is 4 or 8.

So: (138-2) (138-2)

————=4 x=34 ————=8 X= 17

X X

A: If there are 34 pages, put 4 pages on each page. If there are 17 pages, put 8 pages per page.

Lingling has 36 digital cards, and the numbers written on them are multiples of 3 or 4. Among them, there are 24 cards with multiples of 3 and 27 cards with multiples of 4. So how many cards with multiples of 3 and multiples of 4 are there?

(24+27)-36= 15 (Zhang)