"Order of Operations" tells us in what order to do things to an equation. Generally, when doing math, the order is PEMDAS.
P #-># Parentheses. This means do everything within parentheses. If there are multiple, do them all in the PEMDAS order as well. (Useful to know, but useless in this problem)
E #-># Exponent. If you have anything to the power of another thing, figure those out first. (Useful to know, useless for this problem)
MD #-># Multiplication & Division. Any sort of multiplication or division in the problem, you do these next. If there's multiple of them, you do them in the order from left to right.
AS #-># Addition & Subtraction. Any sort of addition and subtraction in the problem, you do these last. If there's multiple of them, do them from left to right.
However, in your problem
#y/6-5=1#
you are solving for the value, rather than just simplifying an expression. So we do this in the opposite order (SADMEP).
First, we see there's subtraction of a 5. So let's undo that by adding 5 to each side.
#y/6color(red)(cancel(-5))+color(red)(cancel(5))=1+5#
#y/6=6#
Next, we see there's division. So let's undo that by multiplying each side by 6.
#y/color(red)(cancel(6))*color(red)(cancel(6))=6*6#
Simplify this final step, and we get
#y=36#
