Answer:
x = -1/2
Step-by-step explanation:
To solve the equation, we first need to combine like terms:

Simplify further:

Divide by -12 on both sides to get:

To check the solution, plug x back into the original equation and check if we get the correct answer:



Thus, it checks out and our answer is correct.
The speed of wind and speed of plane in still air are 23 and 135
km/h respectively.
<u>Step-by-step explanation:</u>
Let the speed of wind and speed of plane in still air are w and p km/h respectively.
The effective speed on onward journey was
................(1)
The effective speed on return journey was
..............(2)
Adding equation (1) and equation (2) we get,
⇒ 
⇒ 
⇒ 
Putting value of
in
we get:
⇒ 
⇒ 
⇒ 
Therefore ,The speed of wind and speed of plane in still air are 23 and 135
km/h respectively.