1963 AHSME Problems/Problem 40
Let and
. Cubing these equations, we get
and
, so
. The left-hand side factors as
However, from the given equation , we get
. Then
, so
.
Squaring the equation , we get
. Subtracting this equation from the equation
, we get
, so
. But
and
, so
, so
. Cubing both sides, we get
, so
. The answer is (C).