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Question

Quantitative Aptitude Question on Algebra

If 92x181x1=19449^{2x – 1} – 81^{x-1} = 1944, then x is

A

3

B

94\frac{9}{4}

C

49\frac{4}{9}

D

13\frac{1}{3}

Answer

94\frac{9}{4}

Explanation

Solution

9(2x1)81(x1)=19449^{(2x−1)}−81^{(x−1)}=1944
9(2x1)9(2x2)=19449^{(2x−1)}−9^{(2x−2)}=1944
92x2×8=1944,9^{2x−2}×8=1944,
3(4x4)=353^{(4x−4)}=3^5
4x4=54x−4=5
x=94x=\frac{9}{4}