we know that
[Total Cost of the 12 pencils]=[sales price 12 pencils]+[sales taxes]
Total Cost of the 12 pencils=$6.70
sales taxes=$0.46
[sales price 12 pencils]=[Total Cost of the 12 pencils]-[sales taxes]
[sales price 12 pencils]=[$6.70]-[$0.46]------->$6.24
[sales price 12 pencils]=$6.24
[sales price 1 pencil]=$6.24/12----------> $0.52
the answer is
the sales price of 1 pencil before the sales tax was added is $0.52