Cut out a square of the same size at each corner of the square paperboard with side length of 16 cm, and fold it into the sum of a cuboid without cover. 1. If the side length of the cut small square is xcm, please use X to indicate the volume of the carton. 2. When the side length x of the cut small square is 3cm and 3.5cm respectively, the volume of the two folded open cuboid cartons is compared.

Cut out a square of the same size at each corner of the square paperboard with side length of 16 cm, and fold it into the sum of a cuboid without cover. 1. If the side length of the cut small square is xcm, please use X to indicate the volume of the carton. 2. When the side length x of the cut small square is 3cm and 3.5cm respectively, the volume of the two folded open cuboid cartons is compared.

The volume V is (16-2x) x: v = (16-2x) ^ 2 (square) x (the simplification is v = 4x ^ 3-64x ^ 2 + 256x)
In the second question, just bring the value into x, 3cm: 30cm ^ 3; 3.5cm: 31.5cm ^ 3

A mathematical problem of addition and subtraction
In a subtraction formula, the sum of the subtracted, the subtracted and the difference is 256. The subtraction is 32 larger than the difference. What is the difference?

The sum of the subtracted, the subtracted and the difference = 2 * (subtraction + difference) = 256
Subtraction difference = 32
Subtraction = 80,
Difference = 80-32 = 48

Those who know how to add and subtract will come in and answer!
There is a question in the sixth grade textbook: a man spent 60 yuan to buy a cow. He sold it for 70 yuan. Then he bought it for 80 yuan and sold it for 90 yuan. Did he earn or lose? If he did, how much did he earn? If he lost, how much did he lose?

70 + 90 = 160 (yuan) 60 + 80 = 140 (yuan) 160-140 = 20 (yuan) a: he earned 20 yuan