几道简算题4

问题描述:

几道简算题4
1.1/17×4/9+5/17×1/9
2.1/7×3/4+3/7×1/6+6/7×1/12
3.5/9×79又16/17+50×1/9+1/9×5/17
4.5/17×3/8+1/15×7/16+1/15×3又1/2

1.1/17×4/9+5/17×1/9 = 1/17×4/9+1/17×5/9= 1/17×(4/9+5/9)= 1/17 2.1/7×3/4+3/7×1/6+6/7×1/12= 3/7×1/4+3/7×1/6+3/7×1/6= 3/7×(1/4+1/6+1/6)= 3/7×7/12= 1/43.5/9×79又16/17+50×1/...