拜托了、六年级奥数题

①.51又2/3×3/5+71又3/4×4/7+91又4/5
=50又5/3×3/5+70又7/4×4/7+91又4/5
=30+1+40+1+91又4/5
=163又4/5
②.299又1/16×1/15+139又1/8×1/7＋59又1/4×1
=（300-15/16）*1/15+（140-7/8）*1/7+60-3/4
=20-1/16+20-1/8+60-3/4
=100-15/16
=99又1/16

①.51又2/3×3/5+71又3/4×4/7+91又4/5 拆分法
=(50+5/3)x 3/5 + (70+7/4)x 4/7+ 91又4/5
=30+1+40+1+91又4/5
=163又4/5
②.299又1/16×1/15+139又1/8×1/7＋59又1/4×1
=(300-15/16)/15+ (140-7/8)/7+59又1/4
=20-1/16+20-1/8+60-3/4
=100-1/16-2/16-12/16
=100-15/16
=99又1/16

①.51又2/3×3/5+71又3/4×4/7+91又4/5
=(50+5/3)*3/5+(70+7/4)*4/7+91+4/5
=30+1+40+1+91+4/5
=163+4/5

②.299又1/16×1/15+139又1/8×1/7＋59又1/4×1
=(300-15/16)*1/15+(140-7/8)*1/7+59+1/4
=20-1/16+20-1/8+59+1/4
=99+(1/4-1/8-1/16)
=99+1/16