How would i use the change of base formula for this problem?

Question

Approximate the logarithm using the properties of logarithms, given log_b(2) ≈ 0.3562,

 log_b(3) ≈ 0.5646,

 and log_b(5) ≈ 0.8271

logb(0.125) = ?

Answer 1

I do not see why you need the change of base formula.

log_b(1/8)=log_b(2^-3)=-3log_b2=-3(.3562)=-1.0686