Решить 1. (7а-2,8)×(4.9+3,5а)=0 2. (-2а+6,6)×(4,2а-8,4)=0

1. (7a - 2,8) * (4.9 + 3,5a) = 0 

7a - 2.8 = 0
4.9 + 3.5a = 0

a = 2.8/7
a = -4.9/3.5

a = 0.4
a = -1.4

2. (-2a + 6,6) * (4,2a - 8,4) = 0

-2a + 6.6 = 0
4.2a - 8.4 = 0

a = 6.6/2
a = 8.4/4.2

a = 3.3
a = 2