/ ____________ \
| / ____ |
| / \/ 78 1 |
And|7 + 3 / 1 + ------ + ------------------- <= x, x < oo|
| \/ 9 ____________ |
| / ____ |
| / \/ 78 |
| 3*3 / 1 + ------ |
\ \/ 9 /
$$\frac{1}{3 \sqrt[3]{\frac{\sqrt{78}}{9} + 1}} + \sqrt[3]{\frac{\sqrt{78}}{9} + 1} + 7 \leq x \wedge x < \infty$$
(x < oo)∧(7 + (1 + sqrt(78)/9)^(1/3) + 1/(3*(1 + sqrt(78)/9)^(1/3)) <= x)
____________
3 ___ 3 / ____ 2/3
\/ 3 *\/ 9 + \/ 78 3
[7 + --------------------- + -----------------, oo)
3 ____________
3 / ____
3*\/ 9 + \/ 78
$$x\ in\ \left[\frac{3^{\frac{2}{3}}}{3 \sqrt[3]{\sqrt{78} + 9}} + \frac{\sqrt[3]{3} \sqrt[3]{\sqrt{78} + 9}}{3} + 7, \infty\right)$$
x in Interval(3^(2/3)/(3*(sqrt(78) + 9)^(1/3)) + 3^(1/3)*(sqrt(78) + 9)^(1/3)/3 + 7, oo)