помогите 6 класс даю много баллов​

а) 2 2/3 - 3/4 * 4/9 = 2 2/3 - 1/3 = 2 1/3

б) 3 1/2 * 2 - 1/3 = 7/2 * 2 - 1/3 = 7 - 1/3 = 21/3 - 1/3 = 20/3 = 6 2/3

в) 2/5 * 1/2 - 7/25* 5/7 = 1/5 - 1/5 = 0