A geologist records log8(90)−log8(9)\\log_{8}(90) - \\log_{8}(9)log8(90)−log8(9). Simplify using log rules.
log8(81)\\log_{8}(81)log8(81)
log8(9)\\log_{8}(9)log8(9)
000
log8(10)\\log_{8}(10)log8(10)