Question

Когда в один вагон загрузили 9 тонн ,а в другой -12 тонн груза,то массы груза в обоих вагонах стали равны.Сколько тонн груза было в первом вагоне ,если во втором было 69 тонн.

Answer 1

69+12=81(тонн)-во 2 вагоне
81-9=72(тонны)- было в 1 вагоне
Ответ:72 тонны

Answer 2

Problem Analysis

The problem states that when 9 tons of cargo were loaded into one train car and 12 tons into another, the masses of the cargo in both cars became equal. We need to determine the mass of the cargo in the first train car, given that the second car had 69 tons of cargo.

Solution

Let's denote the mass of the cargo in the first train car as x tons. According to the problem, the total mass of the cargo in both train cars became equal after loading. This can be represented by the equation: x + 9 = 12 + 69

Calculation

Let's solve for x: x = 12 + 69 - 9

x = 72

Answer

So, the mass of the cargo in the first train car was 72 tons.