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Mathematical problems of formulas and equations. . Be sure to hurry. Solve by equation. . The process can be written. .
1. Solution: Let the middle natural number be X, then the former number is x- 1 and the latter number is x+ 1. According to the meaning of the question, the equation is established.

(x- 1)+x+(x+ 1)= 135

The solution is x=45.

That is, the natural number in the middle is 45, so the former number is 44 and the latter number is 46.

A: These three adjacent natural numbers are 44, 45 and 46 respectively.

2. solution: let the speed of b car be x km/h, and establish the equation according to the meaning of the question.

(x+60)*2.5=360-35

The solution is x=70.

That is, the speed of car B is 70 km/h.

If you consider the situation after the meeting, you can do this. )

Let the speed of B car be ykm/h, and establish the equation according to the meaning of the question.

(x+60)*2.5=360+35

The solution is x=98.

That is, the speed of car B is 98 km/h.

(The word "Hui" in the title is still 70km/h)

3. Solution: Assuming that car B can catch up with car A within x hours, the equation is established according to the meaning of the question.

(80-60)*x=60*2

The solution is x=6.

A: The B car can catch up with the A car in six hours.

4. solution: let their original price be x yuan, and establish the equation according to the meaning of the question.

0.5 x+0.6 x = 990

The solution is x=900.

A: Their original price is 900 yuan.