小学六年级数学上册教材解答

6.5x = 15/19 8/21x = 4/15 x÷4/5 = 15/28

5x÷5 = 15/19÷5 8/21x÷8/21 = 4/15÷8/21x÷4/5×4/5 = 15/28×4/5

x=3/19 x=7/10 x=3/7

2/3÷1/4 = 12

2/3x÷1/4×1/4 = 12×1/4

2/3x=3

2/3÷2/3 = 3÷2/3

x =9/2

7.6 ÷ 3/50 = 100(小时)

8.3分钟= 180秒180 ÷ 9/100 = 2000(张)

9.12 ÷ (1/2× 3) = 8(天)或12 ÷ 1/2 ÷ 3 = 8(天)。