[tex] 216 = 6^{4x+ 11} [/tex]
[tex] 6^3 = 6^{4x+ 11} [/tex]
[tex] 3 = 4x + 11 [/tex]
[tex] 4x = 3 - 11 [/tex]
[tex] 4x = -8 [/tex]
[tex] x = -2 [/tex]
Answer: (c) x = -2