How do I solve this logarithm?

Question

Log10 4 + log10 w = 2
The part I don't understand is the 2 at the end. How do I change that in order to solve the problem?

I'm having the same problem with this logarthim as well:
3 log5 (x^2+9) - 6 = 0

Answer 1

Log(4) + log(w) = 2

base 10 - is the same as log (4w) = 2

10^2=100=4w
w=25

raising it to the base, allows you to undo the function

3 log5 (x^2+9) - 6 = 0
log5 (x^2+9) =6/3

5^(2)=25=x^2+9

==x^2-16 = (x+4)(x-4)

x=4, -4

Answer 2

Log10 4 + log10 w = 2

log_10 4w=2
4w=100
w=25

3 log5 (x^2+9) - 6 = 0
3log_5 (x^2+9)=6
log_5 (x^2+9)=2
x^2+9=25
x^2-16=0
(x+4)(x-4)=0
x=4, -4

Answer 3

Log10 4 + log10 w = 2
It is understood that if you use log that the base is 10
log 4 +log w = 2 is equivalent to your expression
Now log a + log b = log a*b, so
log 4 +log w = log 4w = 2
This means that 10^2= 4w, or
4w=100
w = 25

Check log 4 = log 25 = log 4*25 =log 100 = 2 because 10^2=100