How do you solve these logarithmic functions?

1) log x= -2
2) log(3x+5)= 2

They seem so simple but my teacher didn't lecture very well on this... Can you please explain how to do them?

Anonymous2009-12-08T19:22:32Z

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You haven't indicated the base of the logarithms, so in these cases we assume the base is 10.

1) 10^-2 = x, or x = 1/100

2) 3x+5 = 10^2,

i.e. 3x+5 = 100,

so x = 95/3

nozar nazari2009-12-09T03:27:07Z

1) x=10^-2=1/100

2) 3x+5=10^2=100 , 3x=95 , x=95/3=31.67
God bless you.