Question

có thể tách từng phần/ bài ra làm cũng đc ạ. Thanks :33

Answer 1

Câu 2:

a:

\(10=2\cdot5;12=2^2\cdot3;18=3^2\cdot2\)

=>\(BCNN\left(10;12;18\right)=3^2\cdot2^2\cdot5=180\)

 \(x⋮10;x⋮12;x⋮18\)

=>\(x\in BC\left(10;12;18\right)\)

=>\(x\in B\left(180\right)\)

=>\(x\in\left\{180;360;540;...\right\}\)

mà 100<x<500

nên \(x\in\left\{180;360\right\}\)

b:

\(72=2^3\cdot3^2;24=2^3\cdot3;120=2^3\cdot3\cdot5\)

=>\(ƯCLN\left(72;24;120\right)=2^3\cdot3=24\)

 \(72⋮x;24⋮x;120⋮x\)

=>\(x\inƯC\left(72;24;120\right)\)

=>\(x\inƯ\left(24\right)\)

=>\(x\in\left\{1;2;3;4;6;8;12;24\right\}\)

mà 5<x<10

nên \(x\in\left\{6;8\right\}\)