It is not allowed to list equations 1. A rectangular playground, 450 meters long and 231 meters wide, with trees planted at the four corners and all around. The distance between two neighboring trees is equal. How many trees should be planted at least? If you buy a sapling for 8 yuan, how much will it cost to buy these trees? 2. Uncle Wang has three children. The eldest goes home once every three days, the second goes home once every four days, and the third goes home once every six days?

It is not allowed to list equations 1. A rectangular playground, 450 meters long and 231 meters wide, with trees planted at the four corners and all around. The distance between two neighboring trees is equal. How many trees should be planted at least? If you buy a sapling for 8 yuan, how much will it cost to buy these trees? 2. Uncle Wang has three children. The eldest goes home once every three days, the second goes home once every four days, and the third goes home once every six days?

1： ﹙450, 231﹚＝3
(450 + 231) × 2 △ 3 × 8 = 3632 yuan
2: [3, 4, 6] = 12 days
1＋12＝13
The next time is to go home together on October 13

It is necessary to calculate the comprehensive formula or equation
1. For two steel pipes, the first one is 2 / 3, the second one is 2 / 3, and the remaining two are the same length?
2. For a steel pipe, 30% of it was sawed in the first time, 0.9 m in the second time, and 1 / 4 of it was left in the end?
1. For two steel pipes, the first one is 2 / 3, the second one is 2 / 3, and the remaining two are the same length. Which is the length of the original two?
2. For a steel pipe, 30% of it was sawed in the first time, 0.9 m was sawed in the second time, and 1 / 4 of it was left in the end. How long was the steel pipe?

(1) Let the first length x and the second length y, then
X - (2 / 3) x = Y-2 / 3, i.e
(1/3)x=y-2/3;
When x = y = 1, it is obvious that the above equation holds;
When x = 2, y = 4 / 3, then x > y;
When x = 1 / 2, y = 5 / 6, then X