5/7x=35

x=49

Method 2 35÷5/7=49 (page)

2. Method 1: Solution: Suppose an adult needs about x grams of calcium every day.

3/8x=3/ 10

x=4/5

Method 2: 3/ 10 ÷ 3/8 = 4/5 (g)

3. solution 1 solution: suppose the speed of the spacecraft is x km/s.

40/57x=8

40/57x÷40/57=8÷40/57

x=57/5

Solution 2 8÷40/57=57/5 (km/s)

Solution: let this bucket weigh x kilograms.

x- 1/ 10x=9

( 1- 1/ 10)x=9

x=9÷9/ 10

x= 10

Methods 29 ÷ (1-110) =10 (kg).

5. 15/ 16÷3= 15/ 16× 1/5=3/ 16 12/25÷8= 12/25× 1/8=3/50

8÷4/5=8×4/5= 10 2 1/40÷7/8=2 1/40×8/7=3/5

16÷2/ 17= 16× 17/2= 136 7/24÷6/49=7/24× 17/2=343/ 144

18/35÷0.6×2/3 4/9× 15/ 16÷5/6

=35/ 18 × 10/6×2/3 =5/ 12×6/5

=6/7× 2/3 = 1/2

= 12/2 1=4/7

( 2-0.6)÷7/ 15 35/64÷( 1/8+3/4)

= 1.4× 15/7 =35/64÷7/8

=3 =35/64×8/7

=5/8

6. (1500+1000) × 3/5 =1500 (yuan)

7.48+48÷4/5= 108 (ten thousand units)

8.5200÷52/55=5500 (km

9.( 1) 24 ÷ 1/2 = 48 (pieces)

First prize: 48× 1/6 = 8 (pieces)

Second prize: 48× 1/3 = 16 (pieces)

(2) 48÷ 120=2/5

10.3/5x = 25/72 8/9x = 1/6× 16/5 1

3/5x÷3/5 = 25/72÷3/5 8/9x÷8/9 = 8/ 153÷8/9

x = 125/2 16 x = 1/ 17

x÷6/35=26/45÷ 13/25

x÷6/35×6/35= 10/9×6/35

x=4/2 1

11.2/5 ÷ 4 =110 (1-2/5) ÷1/kloc-0 = 6 (.

12. (1) 28 ÷1/5 =140 (pieces)

(2)80÷( 1-4/5)=400 (weeks)

13.1804 ÷ 39/40 ≈1850 (ten thousand tons)

14. solution: suppose there are about x million people in Henan.

x- 1/46=9000

( 1- 1/46)x=9000

45/46x=9000

45/46 times 45/46=9000 times 45/46.

x=9200