Two balls move towards each other at a speed of 2 and 3 m / s. After collision they are repelled with a speed

Two balls move towards each other at a speed of 2 and 3 m / s. After collision they are repelled with a speed: the first 4 m / s second 1 m / s. What is the mass of the first ball if the mass of the second is 0.3 kg

Let the mass of the first ball be x kg. Let’s write the law of conservation of momentum.
2x – 3 * 0.3 = -4x + 1 * 0.3
Let’s solve the resulting equation:
6x = 1.2
x = 0.2