Question

В одной цистерне в 4 раза меньше нефти, чем во второй. После того как в первую цистерну добавили 20 т нефти, а из второй откачали 19 т, нефти в обеих цистернах стало поровну. Сколько тонн нефти было в каждой цистерне первоначально?

Answer 1

Первая цистерна - Х.
Пишем такое выражение
Х + 20 = 4*Х - 19
Упрощаем
3*Х = 20+19 = 39
Находим Х
Х = 39 : 3 = 13 т -  в первой - ОТВЕТ
4*Х = 13*4 = 52 т - во второй - ОТВЕТ 

Answer 2

Пусть в первой х т, тогда во второй 4х . По условию задачи
Х+20 = 4х-19
20+19 = 4х - х
39 = 3х
Х= 39 :3
Х= 13 т в первой

13*4= 52 т во второй
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Проверка
13 +20 = 52-19
33 = 33

Answer 3

Problem Analysis

We are given two tanks, and the amount of oil in one tank is four times less than the amount in the other tank. After adding 20 tons of oil to the first tank and removing 19 tons from the second tank, the amount of oil in both tanks becomes equal. We need to determine the initial amount of oil in each tank.

Solution

Let's assume the initial amount of oil in the first tank is x tons. Since the amount of oil in the second tank is four times less, the initial amount of oil in the second tank is (x + 4x) = 5x tons.

After adding 20 tons of oil to the first tank, the total amount of oil in the first tank becomes (x + 20) tons. After removing 19 tons from the second tank, the total amount of oil in the second tank becomes (5x - 19) tons.

According to the given condition, the amount of oil in both tanks becomes equal. Therefore, we can set up the following equation:

(x + 20) = (5x - 19)

Now, let's solve this equation to find the value of x.

(x + 20) = (5x - 19) x + 20 = 5x - 19 20 + 19 = 5x - x 39 = 4x x = 39/4 x = 9.75

So, the initial amount of oil in the first tank was 9.75 tons, and the initial amount of oil in the second tank was 5x = 5 * 9.75 = 48.75 tons.

Therefore, initially, there were 9.75 tons of oil in the first tank and 48.75 tons of oil in the second tank.

Answer

The initial amount of oil in each tank was 9.75 tons and 48.75 tons, respectively.