if \(3^{(x-y)}=27\) and \(3^{(x+y)}=243\), then \(x\) is equal to:
Answer: C
\(3^{x-y} =27 = 3^{3} \Leftrightarrow x-y=3\) ...(i)
\(3^{x+y}=243=3^{5} \Leftrightarrow x+y=5\) ...(ii)
On solving (i) and (ii), we get \(x=4\).