1) calculam [45;56;37] = 2520 45 = 3²*5
56 =2³ * 7
35 = 5*7
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[45;56;35]= 2³ * 3² *5*7 =2520
2) efectuam amplificarile si insumarea termenilor
[tex]\frac{56*45+45*9+72*21}{2520}=\frac{2520+405+1512}{2520}=\frac{8037}{2520}=\frac{893}{280}\\
Obs.\;Am\;simplificat\;cu\;9[/tex]