Răspuns :
3a* (-2)- 2* (-2)(a+3)=18
-6a +4(a+3) = 18
-6a +4a +12 = 18
-2a = 18-12
-2a = 6
2a = -6
a = -3
-6a +4(a+3) = 18
-6a +4a +12 = 18
-2a = 18-12
-2a = 6
2a = -6
a = -3