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For a particular 5 hours journey, Alex travelled at an average speed of (2x + 5) km/h for

the first 2 hours. He then travelled at an average speed of (3x - 5) km/h for the last 3
hours to complete his journey.

(a) Write down an expression, in terms of x, to represent the distance travelled by
Alex in the first 2 hours of his journey


User Joe Orost
by
6.7k points

1 Answer

2 votes

Answer:

4x + 10

Explanation:

Given

Let


t = time


s = speed

So:


t = 2; s = (2x +5) --- first 2 hours


t = 3; s = (3x -5) --- last 3 hours

Required

Distance covered in the first 2 hours

Distance (d) is calculated as:


Distance = speed * time

i.e.


d = s * t

For the first 2 hours, we have:


t = 2; s = (2x +5)

So:


d = (2x + 5) * 2

Open bracket


d =2x * 2 + 5 * 2


d =4x + 10

Hence, the distance covered in 4x + 10

User Rhand
by
7.5k points