using static System.Console;

​

public class Program {

    public static void Main() {

        var vetor = new Vetor(3, 4);

        var vetor2 = vetor * 2f;

        WriteLine($"X = {vetor2.X}, Y = {vetor2.Y}");

    }

}

​

public struct Vetor {

    public float X, Y;

    public Vetor(float X, float Y) {

        this.X = X;

        this.Y = Y;

    }

    public static Vetor operator *(Vetor left, float right) {

        return new Vetor(left.X * right, left.Y * right);

    }

}