Question

x chia hết cho 12, x chia hết cho 21 và 100<x<200

 

Answer 1

\(12=2^2.3\\ 21=3.7\\ \Rightarrow BCNN\left(12,21\right)=2^2.3.7=84\\ \Rightarrow x\in BC\left(12,21\right)=B\left(84\right)=\left\{0;84;168;252;...\right\}\\ \text{Mà }100< x< 200\Rightarrow x=168\)

Answer 2

\(x\in BC\left(12;21\right)\)

mà 100<x<200

nên x=168

Answer 3

x = 168