3 × a - (40 - 13) = 3
3а-(27)=3 3а=30 а=30:3 а=10
3 * a - (40 - 13) = 3 3a - 27 = 3 3a = 3 + 27 3a = 30 a = 30 : 3 a = 10 Ответ: a = 10