[tex]\displaystyle\\
\text{Stiind ca a+b=11 determinati } ~x \in N\\\\
a)\\
8a+x+8b=93\\
x + 8(a+b)=93\\
x + 8 \cdot 11 = 93\\
x + 88 = 03\\
c = 93 - 88 = \boxed{\bf 5}\\\\
b)\\
5x+4a+3b=85-2b-a \\
5x =85-2b-a -4a -3b\\
5x = 85- 5a-5b\\
5x = 85 - 5(a+b)\\
5x = 85 - 5\cdot 11\\
5x = 85 -55\\
5x =30\\
x = \frac{30}{5}= \boxed{\bf 6}\\\\
c)\\
a+xb+xa+b=132 \\
x(a+b) + (a+b) = 132\\
11x + 11 = 132\\
11x = 132 - 11\\
11x = 121\\
x= \frac{121}{11} =\boxed{\bf 11}[/tex]
