Question

An aeroplane travelled a distance of 400km at an average speed of x km/hr
on the return journey, the speed was
increasedbby 40km/hr
Write down an expression for the time taken for:
the onward journey
the return journey
If the return journey took 30 minutes
less than the onward journey, write an equation in x and find the value of y.​

Answer 1

Answer:

Step-by-step explanation:

total distance=400km

let the speed be x

increased speed = x+40

s=d/t

400/x-400/(x+40)=1/2

(400x+16000-400x)/(x2+40x)=1/2

32000=x2+40x

x2+40x-32000=0

x2+200x-160x-32000=0

(x+200)(x-160)=0

x=-200

x=160

as speed cannot be negative therefore

x=160kmph