Answer:
x = -3
Step-by-step explanation:
Given:
12x - 9 = 10x - 15
Now, let's add 15 to both sides of the equation.
12x + 6 = 10x
Now, let's subtract 12x from both sides of the equation.
6 = -2x
Now, let's divide both sides by -2.
-3 = x
Answer:
0.5 hour
Step-by-step explanation:
Given
Speed of Dina = 10 km/h
Distance = 20 km
So the time Dina taken to complete the track is:

The time taken by Dina is 2 hours. As masha started with dina but she was 4 km of the path left to cycle,
her distance covered in 2 hours was:

So we know the time and distance:
Now,

We have to calculate the time that will be needed by MAsha to complete the track:
As we know the speed and remaining distance

Masha needs 0.5 hour to complete the track ..
I believe the correct answer is B