Answer:
There are a few rules that we can use here:
ln(a^x) = x*ln(a)
ln(a) - ln(b) = ln(a/b)
ln(1) = 0
So here we want to expand:
ln(1/49^k)
First we can use the second property to get:
ln(1/49^k) = ln(1) - ln(49^k)
using the third property, we have:
ln(1/49^k) = ln(1) - ln(49^k) = 0 - ln(49^k)
ln(1/49^k) = - ln(49^k)
Now we can use the first property to get:
ln(1/49^k) = - k*ln(49)
Now we can use the fact that:
49 = 7*7 = 7^2
then:
- k*ln(49) = -k*ln(7^2) = -2*k*ln(7)
So we have:
ln(1/49^k) = (-2*ln(7))*k
We can expand it anymore because this is a real number "(-2*ln(7))" times a variable k.
