42+4*(12а-5)+(7а-3), при z=2/5

Question

42+4*(12а-5)+(7а-3), при z=2/5

Answer 1

42+48a-20+7a-3=19+55a = 19+55*2/5 = 19+11*2=19+22=41

Answer 2

42 + 4(12a-5) + (7a-3) = 42 + 48a - 20 + 7a - 3= 55a + 19
Если a = 2/5, то
55 * 2/5 + 19  = 22 + 19 = 41