Answer:
Step-by-step explanation:
"When 200 gallons of oil were removed from a tank" algebraically looks like this:
V - 200.
"...the volume of oil left in the tank was 3/7 of the tank's capacity" algebraically looks like this:
3/7(V)
Therefore, the equation is
V - 200 = 3/7(V)
Begin by multiplying both sides by 7:
7(V - 200) = 3V and
7V - 1400 = 3V so
-1400 = -4V so
V = 350 gallons
That's if the volume of the oil in the tank was 3/7 of the tank's capacity.
For the other part of the problem, we set up the equation almost the same, except the 3/7 is a 1/2:
V - 200 = 1/2(V)
Multiplying both sides by 2 gives you
2(V - 200) = V and
2V - 400 = V so
-400 = -V so
V = 400