∵3×27^(n-1)×81^(n-1)=3×3^(3n-3)×3^(4n-4)=3^(7n-6)=3^49
∴7n-6=49
∴n=55 ∕ 7
5x‐9=n(x﹢1)=55(x﹢1) ∕ 7
35x‐63=55x﹢55
x=‐5.9