public void Method_substract_returns_substraction_of_given_doubles()
        {
            //arrange
            var math = new Mathematics();

            //act
            double result = math.Substract(16.1, 6.1);

            //assert
            Assert.Equal(10, result, 4);
        }
        public void Substract_returns_sum_of_given_values_double()
        {
            // ararange
            var math = new Mathematics();

            // act
            var result = math.Substract(3, -0.5);

            //assert
            Assert.Equal(3.5, result);
        }
        public void Method_substract_returns_substraction_of_given_integers()
        {
            //arrange
            var math = new Mathematics();

            //act
            double result = math.Substract(20, 10);

            //assert
            Assert.Equal(10, result);
        }
        public void Substract_returns_sum_of_given_values()
        {
            // ararange
            var math = new Mathematics();

            // act
            var result = math.Substract(10, 20);

            //assert
            Assert.Equal(-10, result);
        }