Eulers - Backwards

Hello everyone.

If I want to write Euler's (Backwards) y(tj)=y(tj-1)+h*f(tj,y(tj)) on the formula x=g(x).

then, what should 'g' and 'x' be?

My attempt so far:

y(tj)-y(tj-1)-h*f(tj,y(tj))=0 x=g(x)

Some help would be appreciated.

Regards Cillian