Question

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
​

Answer 1

Answer:

4x + 10

Step-by-step 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