Respostas

2014-05-05T18:04:09-03:00
A)
log|10| (a) = 0,5
a = 10^0,5
-------------------------
log[10] (b) = 0,7
b = 10^0,7
--------------------------
log [10] (a . b) = 

log [10] (10^0,5 . 10^0,7) = 

log [10] (10^1,2) =

10^1,2 = 10^y

y = 1,2

----------------------------
b)

(a.b/10)^x = (a.b)²

(10^1,2/10)^x = (10^1,2)²

(10^1,2-1)^x = (10^2,4)

(10^0,2x) = (10^2,4)

0,2x = 2,4

x = 2,4 / 0,2

x = 12