<PRE><B>Question 1028084</B>
Let car from A meet at C after d km

It took 1 hour
so speed of car A = d km/h

Speed of car B will be (140-d)

The distance car B has to travel is D km
The distance car A has to travel is (140-d)

time carA - time car B to reach the opposite end = 35 minutes

(140-d)/d - d/(140-d) = 7/12

((140-d)^2 -d^2)/d(140-d) = 7/12
19600 -280d+d^2-d^2= 7d(140-d)/12

19600-280d = (980d -7d^2)/12

235200-3360d=980d-7d^2

7d^2-4340d+235200=0

Find the roots of the equation by quadratic formula							
							
a=	7    	b=	-4340	c=	235200		
							
b^2-4ac=	18835600	-	6585600				
b^2-4ac=	12250000		{{{sqrt(	12250000	)}}}=	3500	
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}							
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}				)/			
x1=(	4340	+	3500	)/	14		
x1=	560						
x2=(	4340	-	3500	)/	14		
x2=	60						
Ignore  value	560					
speed of car A 60 km/h 
speed of car B =80 km/h 

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