Ta có:
\(90=2.3^2.5\)
\(120=2^3.3.5\)
\(BCNN\left(90;120\right)=2^3.3^2.5=360\)
\(UCLN\left(90;120\right)=2.3.5=30\)
\(\Rightarrow\dfrac{BCNN\left(90;120\right)}{UCLN\left(90;120\right)}=\dfrac{360}{30}=12\left(lan\right)\)
Vậy \(BCNN\left(90;120\right)\) gấp \(UCLN\left(90;120\right)\) 12 lần