One tank has 4 times less oil than the second. After 20 tons of oil were added to the first tank and 19 tons

One tank has 4 times less oil than the second. After 20 tons of oil were added to the first tank and 19 tons were drained from the second, the oil in both tanks became equal. How many tons of oil was in each tank initially?

1. Let’s take for x the initial number of tons of oil in the first tank, for y the initial number of tons of oil in the second tank.

2. Let’s compose the equations:

y / x = 4; y = 4x;

x + 20 = y – 19; x – y = – 39; Substitute here the value of y from the first equation:

x – 4x = = – 39;

3x = 39;

x = 13;

y = 13 x 4 = 52.

Answer: the first container originally contained 13 tons of oil, the second contained 52 tons of oil.