From CAT 2017 – Quantitative Aptitude – Algebra – Polynomials, we can see that,
9^(2x-1) – 9^(2x-2) = 1944
It can be written as 3^(4x)/9 – 3^(4x)/81 = 1944
8(3^(4x)/81) = 1944
x =9/4
Option (B)
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