(mathematics) harmonic mean

to study / to learn

way; method; manner

instruction; teaching; school; lesson, class

teach; to instruct; give a lesson

mathematics (field of study)

harmonization, harmony

go together, coordinate, be in harmony with / blend in, fit in

average, mean / balance, uniformity / balance (having equal weight on all sides)

to average / to balance, to make uniform / to balance (prevent from falling)