The formula of t in terms of s ,  ,
 ,  is
 is 

The value of t  when s = 310 ,  = 75 ,
 = 75 ,  = 80 is 2 hours
 = 80 is 2 hours
Step-by-step explanation:
Two trains left the cities A and B at the same time and headed towards
each other 
- The cities are s miles apart
- The first train was traveling at the speed of  mph mph
- The second train was traveling at the speed of  mph mph
- After t hours the two trains met each other
∵ The cities are s miles apart
∵ After t hours the two trains met each other
∴ s =  +
 +  , where
, where  is the
 is the 
    distance that the 1st train moved in t hours and  
 
     is the distance that the 2nd train moved in t hours
∵ s = v t
∴  =
 =  t
 t
∴  =
 =  t
 t
- Substitute them in the equation of s
∴ s =  t +
 t +  t
 t
- Take t as a common factor in the right hand side
∴ s = t (  +
 +  )
 )
- Divide both sides by (  +
 +  )
 )
∴ 
The formula of t in terms of s ,  ,
 ,  is
 is 

∵ s = 310 m/h
∵  = 75 m/h
 = 75 m/h
∵  = 80 m/h
 = 80 m/h
- Substitute these values in the formula of t above
∴ 
∴ t = 2 hours
The value of t  when s = 310 ,  = 75 ,
 = 75 ,  = 80 is 2 hours
 = 80 is 2 hours
Learn more:
You can learn more about distance, speed and time in brainly.com/question/1748290
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