If a(n)=log(base n)2310. Then find the value of a(subscript 15)+a14+a12+a11-a4-a3.
OPTION:
A) -log2310
B) 1
C)-1
D) None of the above

• let 2310=x,
  a15+a14+a12+a11-a4-a3=log(15)x+log(14)x+log(12)x+log(11)x-log(4)x-log(3)x
  =logx/log15 + logx/log14 + logx/log12 + logx/log11 - logx/log4 - logx/log3
  =logx (1/log15 + 1/log14 + 1/log12 + 1/log11 - 1/log4 - 1/log3)
  =logx (-log15-log14-log12-log11+log4+log3)
  =logx (-log15-log14-log12-log11+log12)
  =logx (-(log(15*14*11)))
  =logx (-log2310)
  =logx (-logx)
  =logx (1/logx)
  =1 is the Answer
• 6 years agoHelpfull: Yes(29) No(10)
• you can't write 1/log y as -log y.
  -1 is common when it is given as log (1/y)
• 6 years agoHelpfull: Yes(9) No(4)
• yes you are right @Harshul
• 6 years agoHelpfull: Yes(1) No(0)
• tell me the answer of this question please..
• 6 years agoHelpfull: Yes(0) No(0)
• Please explain these questions answer
• 6 years agoHelpfull: Yes(0) No(0)
• X=2310
  a15+a14+a12+a11-a4 a3=log(15)x+log(14)x+log(12)x+log(11)x-log(4)x-log(3)x
  =logx/log15 + logx/log14 + logx/log12 + logx/log11 - logx/log4 - logx/log3
  By using log formula
  ((X/15)*(x/14)*(x/12)*(x/11))/((x/4)*(x/3))
  Ans is log 2310 do option d)
• 5 years agoHelpfull: Yes(0) No(0)