5680/8=710 8130/30=271
710*7=4970 4970-271=4699
5/12+1/60=25/60+1/60=26/60
(68,37-у)÷6.15=8.2
68,37-у=8.2×6.15
68.37-у=50.43
-у=50.43-68.37
-у=-17.94
у=17.94
НОК (5,6,7)=5*6*7=210
210к ,где к=1,2,3,4.
210,420,630,840.
Ответ: <span>210,420,630,840.</span>