Question

considerando log 2 = 0,301, log 3 = 0,477 e log 7 = 0,845, calcule: log 0,07

Answer 1

log 0,07 ==> log (7.10^-2)
log 7 - 2log10 ==> 0,845 -2(1)

0,845 - 2 ==> - 1,155

Answer 2

$log~0,07=log(\frac{7}{100})\\\\log~0,07=log~(\frac{7}{10^{2}})\\\\log~0,07=log~7log~10^{2}\\\\log~0,07=0,845-2\cdot log~10\\\\log~0,07=0,845-2\\\\\\\boxed{\boxed{log~0,07=-1,155}}$