39×148/169+148×86/149+48×74/169 41又1/3×3/4+51又1/4×4/5+61又1/5×5/6

问题描述:

39×148/169+148×86/149+48×74/169 41又1/3×3/4+51又1/4×4/5+61又1/5×5/6