If (5^7)(9^4)=3(15^x), what is the value of x?	Choose the most appropriate option.
A) 7
B) 9
C) 11
D) 13
E) 15

Rationale: "( 5 ^ 7 ) ( 9 ^ 4 ) = 3 ( 15 ^ x ) = > 5 ^ 7 * 3 ^ 8 = 3 * 3 ^ x * 5 ^ x = > 5 ^ 7 * 3 ^ 8 = 3 ^ ( x + 1 ) * 5 ^ x value of x = 7 answer a"
Answer: A