Question

( log _{7} x+log _{13} x=1 )
( x=139 x^{7}=7^{log _{12} 13} )
( log _{7} x+lg _{13} 13 x^{7}=1 )
( -1 log _{7} 7^{log _{13} 13}+log _{13} 15^{log _{13} 7}=1 )
( =log _{k} 13+log _{k} 7=1 )
( -lg _{k}(3 x+)=lg _{16} k )
( k=13 times 7 )
is dumuli
( (A)^{frac{K u}{d(B)}} )

# 11 If log7 x + log13 x = 1 and x = 13logh? then ) is divisible by (A) 7 (B) 13 (C) 17 (D) 119

Solution