Find the logarithm using the change of base formula log7 40

Find the logarithm using the change of base formula

log7 40=

(7 is the base) I didnt know how to type it below

Thank you

Solution

log_a^b =( log₁₀^b) / (log₁₀^a)

log₇⁴⁰ = ( log₁₀⁴⁰) / (log₁₀⁷)

( log₁₀⁴⁰) = 1.6020

(log₁₀⁷) = 0.8450

log₇⁴⁰ = 1.8958