<PRE><B>Question 754857</B>
Write a distance equation for each statememet
dist = speed * time
:
when a car travel at steady speed of v(km/h) on the main road,
 it covers a distance of s(km) in two hours.
2v = s
or
2v - s = 0
: 
if the same car travels at a steady speed of 2v(km/h) it cover
 (s+5)km in two hours.
2*(2v) = (s+5)
Rearrange and use elimination with the 1st equation
4v - s = 5
2v - s = 0
---------------subtraction eliminates s, find v
2v = 5
v = 5/2
v = 2.5 km/hr is the original speed, 5 km/hr is the final speed
:
:
Check this by finding the distance (s)
2(2.5) = 5 km
2(5) = 10 which is s+5




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