Note that this problem is given as
(m - n)/2
where the numerator is m - n and then the denominator is 2.
You will need to find the value in the numerator, then divide by 2.
show steps how you got your answer
In order to isolate any term from an equation we need to clear out any different variable or numbers different from the one we want

in this case I is being multiplied by R, so we need to do the opposite which is divide in order to eliminate

But since this is an equality we must do it on both sides so de equation does not get altered

Then we simplify the equation