Answer: A. There were 500 liters in the tank when the leak started, and it is decreasing by 9 liters per minute.
Step-by-step explanation:
This equation is in the form; y =mx + c.
<em>c</em> in this equation is the value of y when x is at 0.
<em>c</em> in the above formula is 500 which means that the number of litres (y) at zero minutes(x) is 500 litres.
<em>m</em> is the rate of change as a result of a change in x.
<em>m</em> in this equation is -9 which means that the water is reducing by 9 litres every minute (x).
A. y = 2x - 3
This is the correct answer
You need to find the total distance and the total time. The total distance is two times the distance to school, 2d.s=d/t=>t=d/sWhere s is speed, d is distance and t is time. So the time taken to get to school is:d/s1and the time taken to get back is:d/s2so the total time is:d/s1+d/s2=d(1/s1+1/s2)So, as speed = distance/time, divide the total distance by the total time:2d/d(1/s1+1/s2)=2/(1/s1+1/s2)=2/(1/20+1/40)=80/3≈26.7km/hr
