A. The distance between B and a is 450 km. Vehicle a and B start from a and B at the same time and run in opposite directions. It is known that the speed of vehicle a is 120 km / h If the speed of vehicle B is 80 km / h and the distance between the two vehicles is 50 km, the value of B is ()

A. The distance between B and a is 450 km. Vehicle a and B start from a and B at the same time and run in opposite directions. It is known that the speed of vehicle a is 120 km / h If the speed of vehicle B is 80 km / h and the distance between the two vehicles is 50 km, the value of B is ()

Time = (450-50) / (120 + 80) = 2 hours
Or (450 + 50) / (120 + 80) = 2.5 hours
Then the value of is (2 or 2.5)

A. The distance between B and a is 450 km. A and B start from a and B at the same time and run in opposite directions. It is known that the speed of a is 120 km / h and that of B is 80 km / h. After t hours, the distance between two vehicles is 50 km, then the value of T is ()
A. 2 or 2.5B. 2 or 10C. 10 or 12.5d. 2 or 12.5

(1) When car a and car B do not meet, according to the meaning of the question, we get 120t + 80t = 450-50, and the solution is t = 2; (2) when the two cars meet and the distance between them is 50km, according to the meaning of the question, we get 120t + 80t = 450 + 50, and the solution is t = 2.5

A. The distance between B and a is 450 km. A and B start from a and B at the same time and run in opposite directions. It is known that the speed of a is 120 km / h and that of B is 80 km / h. After t hours, the distance between two vehicles is 50 km, then the value of T is ()
A. 2 or 2.5B. 2 or 10C. 10 or 12.5d. 2 or 12.5

(1) When car a and car B do not meet, according to the meaning of the question, we get 120t + 80t = 450-50, and the solution is t = 2; (2) when the two cars meet and the distance between them is 50km, according to the meaning of the question, we get 120t + 80t = 450 + 50, and the solution is t = 2.5