Question

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

Answer 1

Было в первой х
было во второй 4х
стало в первой х+20
стало во второй 4х-19
составим уравнение
4х-19=х+20
4х-х=20+19
3х=39
х=39:3
х=13 т было в первой
13*4=52 т было в первой
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Answer 2

Problem Analysis

We are given two tanks, and initially, 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 find 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 amount of oil becomes (x + 20) tons. After removing 19 tons from the second tank, the amount of oil becomes (5x - 19) tons.

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

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

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

Equation Solving

Expanding the equation:

x + 20 = 5x - 19

Moving the variables to one side:

x - 5x = -19 - 20

Simplifying:

-4x = -39

Dividing both sides by -4:

x = 9.75

Answer

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

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