Нурланltnurik 2.8-(4.2*a+3.4)+7.1-1.3*a 2.8-4.2*a-3.4+7.1-1.3*a -0.6-4.2*a+7.1-1.3*a 6.5-4.2*a-1.3*a 6.5-5.5*a Ответ: 6.5-5.5*a