Correct option is A
Given:
(429)3×(294)2×(429)11=(294)9m+7
Formula Used:
Laws of indices: apaq=ap+q,(ba)−n=(ab)n
Solution:
(429)3×(429)−2×(429)11=(294)9m+7
(429)11+3−2=(294)9m+7
(429)12=(429)−(9m+7)
Equate powers:
12=−(9m+7)⟹9m=−19⟹m=−919.