Răspuns:
g) a=2
h) a=137
Explicație pas cu pas:
g) [12:(9-2a-2)]×4=10+6
[12:(7-2a)]×4=16
12/(7-2a) ×4=16
48/7-2a=16
48=16(7-2a) |:16
3=7-2a
2a=7-3
2a=4 |:2
a=2
h) [(a+107)×2+5]×2-186=800
(2a+214+5)×2-186=800
(2a+219)×2-186=800
4a+438-186=800
4a+252=800 |-252
4a=548| :4
a=137