Question

Resolva os sistemas : log x-log=2, log x+log y=0

Answer 1

log x-logy=2 (i)

log x+log y=0 (ii)

Some (i) com (ii):

2logx = 2 .:. logx = 1 .:. x = 10

Ora, se logx = 1, então substituindo em (i):

1  - logy = 2 .:. -logy = 2-1 = 1 .:. logy = -1 .:. y = 0,1

Answer 2

Olá

{ log x - logy=2  

{ log x + log y=0              ---> vamos somar as duas colunas

2log x  + 0 = 2

2log x = 2

log x = 2/2

log x = 1                 --> aplicar a regra geral do log

10¹ = x

x = 10

Se x = 10 ---> log 10 + log y = 0    -->   1 + logy = 0   -->  logy = -1

10^-1 = y

y = 0,1