(6+9)x= 1.5

15x÷ 15 = 1.5÷ 15

x=0. 1

5. 13.2 x+9x = 33.3 8x-3x = 105

22.2 x÷22.2 = 33.3÷22.2 5x÷5 = 105÷5

x= 1.5 x=2 1

5.4x+x = 12.8 x-0.36 x = 16

(5.4+ 1)x= 12..8 ( 1-0.36)x= 16

6.4÷6.4= 12.8÷6.4 0.64x÷0.64= 16÷0.64

x=2 x=25

6. Solution: Let the smaller natural number be X and the other natural number be x+ 1.

x+(x+ 1)=97

2x+ 1- 1=97- 1

2x=96

2x \2 = 96 \2

x=48

x+ 1=48+ 1=49

A: These two natural numbers are 48 and 49 respectively.

7. Solution: Suppose there are X chickens and rabbits.

2x+4x=48

x=8

A: There are 8 chickens and 8 rabbits in each group.

8. Solution: Suppose Xiaoming is X years old and his mother is 3x years old.

3x-x=24

x= 12

3x=3× 12=36

A: Xiaoming 12 years old, and his mother is 36 years old.

9. Solution: Let each set of books have X copies.

2.5x+3x=22

x=4

There are 4 books in each series.

10. Solution: It was supposed to be shipped x times in the afternoon before it was finished.

5×3+5x=35

x=4

A: It will be delivered four times in the afternoon.

Solution: Let the number in □ be X.

24x- 15x= 18

x=2

So □ should fill in 2.

12.3x=x+ 100

2x= 100

x=50