Answer:
Step-by-step explanation:
I can tell you what it represents, but not what it means. Or maybe the units.
V(5/7) means that wherever you see an r on the right hand side, you put in 5/7 where the R is.
V = 4/3 * pi * r^3
V(5/7) = 4/3 * 3.14 * (5/7)^3
V(5/7) = 4/3 * 3.14 * 125 / 343
V(5/7) = 4/3 * 3.14 * 0.3644
V(5/7) = 1.526 cubic units (of whatever the units of 5/7 were to begin with)
