<span>C. 6 is your answer
1/3 = y/18
3y = 18
y = 6</span>
Difference means subtract so we can reduce the choices right away to first and third choices. of the only the first is the difference of squares, namely x² - 4²
We must look at this question in steps
The first half of the journey is travelled at 40 km/h
Half of 100km is 50 km
Using the formula
Distance = Speed x Time
Speed = Distance / Time
Time = Distance / Speed
We can work out the time:
50km / 40km/h = 1.25 hours
Next we look at the second half of the journey
50km at 80km/h
50km / 80km/h = 0.625 hours
Add together both times to work out how long the entire journey took
1.25 + 0.625 = 1.875 hours
Using the Speed formula from before
Speed = 100km / 1.875 =
53 1/3 km/h or 53.3 recurring km/h
A is located, as you look A is past -2 almost hitting -3 making the mark 2.8 so the answer is A
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