If 5^k + 5^k = (5^9)^(5^9) - 5^k, then k = ? Choose the most appropriate option
A) 5^11 - 1  B) 11/2  C) 242  D) 3^10  E) 3^11 - 1
5^k + 5^k = (5^9)^5^9 - 5^k   5*(5^k) = 5 ^ (25 * 5^9 ) = 5^(5^2 * 5^9) = 5^(5^11)   5^k+1 = 5^(5^11)   So k+1 = 5^11   So k = 5^11 -1   5^11 - 1nswer is 5^11 - 1
<result>A</result>
If 5^k + 5^k = (5^9)^(5^9) - 5^k, then k = ?