4=1/4y-2
opposite of subtraction is addition so you want to add 2 to 4 which will cancel out the -2 and you are left with 6=1/4y
6/1/4=1/4y/1/4
since 1/4 is being multiplied by y you want to do the opposite of multiplication which is division to isolate y.
Once you divide you would get 24 (d)