Sameera Travels by coach from Singapore to penang which is 700 kilometres apart to visit our grandparents. He returned to Singapore by car at an average speed which is 30 km per hour greater than that of a coach
i) if the average speed of the car is x km per hour in the time taken for the whole journey is 20 hours, formulate an equation in x and show that it reduces to x^2-100x+1050=0
ii) solve the equation x^2-100x+1050=0
iii) Fime the time taken fot the return journey
IGNORE the RUBBISH posted by the other person!!
With x being the speed of the car, the speed of the coach = x - 30
We then get the following TIME equation:
700(x - 30) + 700x = 20x(x - 30) ------- Multiplying by LCD, x(x - 30)
<====== What was asked to show!
Solving for x will give you the car's speed as: ,
using the quadratic equation formula, completing the square, or by graphing, since this TRINOMIAL cannot be factored with integers.
Having the DISTANCE and speed you should be able to find the time taken to complete the return trip.
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Again, IGNORE the RUBBISH and NONSENSICAL answers, if you can call them that, posted by the other ALWAYS-ALWAYS-WRONG person
SPEED TIME DISTANCE
S to P r 700/r 700
P to S r+30 700/(r+30) 700
TOTAL 20
-----equation to solve, first for r.
The AVERGAE speed for the whole journey is , kilometers per hour.