How to do conditional formatting vs range?

Question

Google Sheets

https://docs.google.com/spreadsheets/d/1vqKnsN_8qQ...

If the value in K1 matches any value in the range C1:J1, then the color of the value of cell K1 would change, for example, the number would turn gray.

It doesn't work like this:
=C1:J1
Although if you specify only one cell, it works.
What am I doing wrong?



And can you make it so that with this formatting, the bold figure becomes not bold?
Because initially they are all fat.

Answer 1

How can K1 not be equal to the whole range?
It is necessary for the function to search in the array and after that check whether it found something or not.
=ЕСЛИОШИБКА(ПОИСКПОЗ(A1;E6:E7;0);0)