|
Substitute (7x-2) with a ->
a^1/3 + (a+7)^1/3 = 3
(a+7)^1/3 = 3 - a^1/3
Raise both sides to the power of 3 ->
a+7 = 27 - 27a^1/3 + 9a^2/3 + a
Substitute a^1/3 with b and muck about ->
2b^3 - 9b^2 + 27b - 20 = 0
Which should be solvable. Remember that b = (7x-2)^1/3
|