Question

Calculati: a) (28;42);[28;42]
b)Verificati relatiile : (28;42)*[28;42]=28*42
DAU COROANA VA ROOOOOOOG REPEDE

Answer 1

 

$\displaystyle\bf\\28=2^2\times7\\42=2\times3\times7\\\\cmmdc=(28;~42)=2\times7=\boxed{\bf14}\\\\cmmmc=[28;~42]=2^2\times3\times7=12\times7=\boxed{\bf84}\\\\Verificare~fara~calcularea~produselor:\\\\(28;~42)\times[28;~42]=\\\\=14\times84=14\times(2\times42)=(14\times2)\times42=28\times42\\\\\implies~\boxed{\bf14\times84=28\times42}$