At the same time, Party A and Party B set out from AB and walked towards each other. When meeting, Party A walked12km more than Party B. After meeting, Party A walked for 4 hours to the place B and Party B walked for 9 hours to the place A, so as to find the distance between AB and the speed of both parties.

Solution: Assuming that the distance traveled by B is S kilometers, then the distance traveled by A is s+ 12 kilometers.

The speed of a is s/4 km/h, and the speed of b = (s+12)/9 km/h.

According to the meaning of the question

(s+ 12)/(s/4)= s/[(s+ 12)/9]

4(s+ 12)？ =9s？

Because s>

therefore

2s+24=3s

S=24 kilometers

AB distance = s+s+12 = 24+24+12 = 60km.

The speed of a = 24/4 = 6 km/h.

The speed of B = (24+12)/9 = 4 km/h.

The distance between Party A and Party B is 56 kilometers. Xiao Ming and Xiao Jie set out from Party A and Party B at the same time and headed for Party A and Party B respectively. After they met on the way, Xiao Ming continued to ride to Party B, arriving at 1.5 hours, and Xiaojie continued to ride to Party A, arriving at 2 hours and 40 minutes, seeking their speed.

Answer: 2 hours and 40 minutes =8/3 hours.

1.5 hours =3/2 hours

Let Xiaoming's speed be a km/h and Xiaojie's speed be b km/h..

3/2a+8/3b=56( 1)

3/2a/b=(8/3b)/a(2)

By (2)

9a？ = 16b？

3a=4b

Replace (1)

2b+8/3b=56

6b+8b=56×3

14b= 14× 12

B =12km/h

A= 16 km/h

Xiao Ming's speed is16 km/h.

Xiaojie's speed is12 km/h.