设第一桶油重x千克,(1- 1 5 )x=44-x+2.8, 4 5 x=46.8-x, 4 5 x+x=46.8-x+x, 9 5 x÷ 9 5 =46.8÷ 9 5 , x=26,44-26=18(千克),答:原来第一桶油重26千克,第二桶油重18千克.