Завдання 1402 - 1500 » 1441 (7-8)

7) 1/6y – (0,5 + 8/9y) = 1/9y – (1/3 + y); 1/6y – 0,5 – 8/9y = 1/9y – 1/3 –y; 1/6y – 8/9y + 8/9y = – 1/3 + 1/2; 1/6y = 1/6; y = 1. 8) 3/5 ∙ (3 – 2z) = 2/5 ∙ (9 – z) – 0,3(z – 9); 9/5 – 6/5z = 18/5 – 2/5z – 3/10z + 27/10; –6/5z + 2/5z + 3/10z = 18/5 + 27/10 – 18/10; –5/10z = 45/10; z = –9.