[tex]\it 2x+3\leq15|_{-3} \Rightarrow 2x\leq12|_{:2} \Rightarrow x\leq6\ \ \ \ (1) \\\\x|18 \ \ \ \ \ (2)\\\\(1),\ (2) \Rightarrow A= \{1,2,3,6\}[/tex]
[tex]\it 2x-1<19|_{+1}\Rightarrow 2x<20|_{:2} \Rightarrow x<10 \ \ \ \ (3) \\ \\ x|14 \ \ \ \ (4) \\ \\ (3),(4) \Rightarrow B=\{1,2,7\}[/tex]
