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
答
39×148/169+148×86/149+48×74/169=39×148/149+86×148/149+24×148/149=(39+86+24)×148/149=149×148/149=14841又1/3×3/4+51又1/4×4/5+61又1/5×5/6=124/3×3/4+205/4×4/5+306/5×5/6=124/4+205/5+306...