(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