Equation: (2+4)x+4(x+ 10)=460, and the solution is x=42, that is, the speed of vehicle A is 42 kilometers per hour.
2.80000÷50= 1600 (m/min)? The approaching speed of two cars.
(80000÷2)÷(50+ 16 2/3)=600 (m/min)? crawl speed
1600-600 = 1000 (m/min) = 1 (km/min) the speed of the express train.
80- 1× (50+ 16 and 2/3)=40/3= 13 and 1/3 (km) The distance between the express train and the second place.