3. The formula (1) represents a number that is 4 times larger than 5 times of A and a number that is 3 times smaller than 2 times of A, and the sum of these two numbers is calculated;

(2) Formulating a number three times larger than X and five times smaller than X, and calculating the difference between these two numbers.

4. The planting area of wheat in a village is 1 hm2, the planting area of rice is 3 times that of wheat, and the planting area of corn is 5? Hm ~ 2, the formula indicates the rice planting area and the corn planting area, and calculates how much the rice planting area is larger than the corn planting area.

Answer:

3.( 1) A number five times larger than A times 4: 5A+4.

The number 3 is less than twice that of A: 2A-3.

Their sum is: (5a+4)+(2a-3) = 7a+ 1.

(2) Numbers greater than 7 times x times 3: 7x+3.

? Number less than -2 times x times 5: -2x-5.

? The difference between these two numbers =(7x+3)-(-2x-5)=9x+8.

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