Solve for Real Roots $$x ^ { 1 / 2 } - 13 x ^ { 1 / 4 } = - 42$$

Multiple Choice

Solve for real roots.
- $$x ^ { 1 / 2 } - 13 x ^ { 1 / 4 } = - 42$$

A) $x = 49,36$
B) $x = 2401,1296$
C) $x = 7,6$
D) $x = - 7 , - 6$