sir your approach is right but just knowing basic of log without solving one can get an answer

1. log value always positive

1. log value can't be zero (bcoz at zero it's undefined)

so. given log(x-7) x-7>0 x>7 // only one value is in option greater than 7 which is 11

1. log value always positive

1. log value can't be zero (bcoz at zero it's undefined)

so. given log(x-7) x-7>0 x>7 // only one value is in option greater than 7 which is 11