You scratch my back...

Hello dear Alan and Torsten! Could you explaine the ex.
" You scratch my back and I’ll scratch yours". I heard it, but I didn’t understand "
Many thanks
Pioneer

Dear Pioneer,

Many thanks for your question. The expression ‘You scratch my back and I’ll scratch yours’ is an old saying that was used to refer to an informal agreement. It usually meant ‘I’ll do this for you and you’ll that for me’.
It’s some kind of a ‘mutualistic’ relationship where two parties benefit from living closely with each other.[YSaerTTEW443543]

TOEIC listening, photographs: An overground pipe[YSaerTTEW443543]

Dear Torsten. In Russian it sounds as: “Hand washes hand” Do you agree with it?
Pioneer

You are exactly right. The German equivalent is the same as the Russian one: ‘one hand washes the other’.[YSaerTTEW443543]

TOEIC listening, photographs: The swimmer[YSaerTTEW443543]

I didn’t find the translation of the word “mutualistic” .What is it?
Pioneer

Dear Pioneer,

A mutualistic relationship is a mutually beneficial association between different kinds of organisms.
‘Mutual’ means ‘directed and received by each toward the other’, ‘reciprocal’.
You might have heard of ‘mutual funds’ or ‘mutual insurance’.[YSaerTTEW443543]

TOEIC listening, photographs: Taking a corner fast[YSaerTTEW443543]

Yes, I’v heard it one week ago.
Many thanks.
Pioneer