Vì x\(⋮\)4;x\(⋮\)-6 => x\(\in\)BC(4;-6)
4=22
-6=2.(-3)
=>BCNN(4;-6)=22.(-3)=-12
=>BC(4;-6)=B(-12)={0;-12;-24;-36;...}
Vì -20 < x < -10
nên x = -12
Vì \(x⋮4\Rightarrow x\in B\left(4\right)\)
\(x⋮6\Rightarrow x\in B\left(6\right)\)
\(\Rightarrow x\in BC\left(4;6\right)\)
\(\Rightarrow x\in\left(...-24;-12;0;12;24...\right)\)
Mà -20<x<-10 => x = -12