Before I ask my question, I'm just wondering if it's ok to keep using this thread to ask any math questions I have from now, to the future rather than create a new topic every time?.

My question that I'm struggling on is:

Make the symbol indicated in square brackets the subject of each of the formula shown:

m = (2(t-an)) / (n(n-1)) [a]

*EDIT

Here is my attempt:

I used

a = 4

n = 2

m = -5 (obtained from doing original equation)

t = 3

m = (2(3-4*2)) = -10 = -5

2(2-1) = 2 =

a = n(n-1) m = -10 = -5 once again

2t -2a = 2

~Just isn't making sense.