7.86 тонн,9х8.3=74.7 __ 6х7.2=43.2 __ 74.7+43.2=117.9 __ 117.9 : 15=7.86
(8,3*9+7,2*6) / (9+6) = 7,86 т
7.86 тонн,9х8.3=74.7 __ 6х7.2=43.2 __ 74.7+43.2=117.9 __ 117.9 : 15=7.86
(8,3*9+7,2*6) / (9+6) = 7,86 т