Question

log 2 = 0,30 , log 3 = 0,47 , log 5 = 0,69, calcular: a) log 15 b) log 18 log 25

Answer 1

Explicação passo-a-passo:

a)

$\sf log~15=log~(3\cdot5)$

$\sf log~15=log~3+log~5$

$\sf log~15=0,47+0,69$

$\sf log~15=1,16$

b)

$\sf log~18=log~(2\cdot3^2)$

$\sf log~18=log~2+log~3^2$

$\sf log~18=log~2+2\cdot log~3$

$\sf log~18=0,30+2\cdot0,47$

$\sf log~18=0,30+0,94$

$\sf log~18=1,24$

c)

$\sf log~25=log~(5^2)$

$\sf log~25=2\cdot log~5$

$\sf log~25=2\cdot0,69$

$\sf log~25=1,38$