1. Connect the following equations.

9x+3x=3.6

12x=3.6

x=0.3

9x-3x=3.6

6x=3.6

x=0.6

8x-0.5x= 120

7.5x= 120

x= 16

4.5x-x= 14

3.5x= 14

x=4

2.8x+7x=44. 1

9.8x=44. 1

x=4.5

x+5.5x= 13

6.5x= 13

x=2

2. Orchard Uncle Zhang has 180 peach and pear trees in his orchard. As we all know, the number of peach trees is exactly four times that of pear trees. How many trees are there?

Solution: There are X pear trees.

x+4x= 180

x=36

Peach tree: 36*4= 144

Try it: If the second condition of the above question is changed to "There are more peach trees than pear trees in the orchard 108", how should the equation be solved?

Solution: There are X pear trees.

x+(x+ 108)= 180

x=36

Peach tree: 36+ 108= 144

How old are the father and son?

Father: I am eight times your age.

Son: I am 28 years younger than you.

Solution: Let the son be X years old.

8x=x+28

7x=28

x=4

Father: 4+28=32 years old