The answer is no solution
Step-by-step explanation:
The equation is
and 
Subtracting these two equations, we get,

Thus,
is not possible.
Hence, the system of equations have no solutions.
The total number of produced details increased by 6.4%
suppose the starting number was x.
suppose x=100
100 +12%= 112
112-5%=106.4
106.4-100=6.4
6.4%
6 - 3 = 3
-2 - (-9) = 7
(3 , 7)