Divided $T between three people X, Y, Z, so that may have twice as much as Z and $m more than three times Y's share. Give answers in their simplest forms of aT+bm, where a and b are real numbers.

I realised that X,Y and Z are names of people, not quantities for calculation, so i use a and b instead, but i can't seem to get the answer, all I know is that we need to use substitution method, but I'm not really on the right track right now...

I don't understand the problem. You've left out too many words.

X+Y+Z = $T
Who has twice as much as Z?
$m more than three times Y?

X+Y+Z = $T
Who has twice as much as Z?
$m more than three times Y?

oh So sorry...
It's supposed to be X has twice as much as Z
and X has $m more than three times Y
Thanks for telling me that, no wonder no one answered for a long time!

X, Y, and T are the amounts that each person gets. You can write these three equations:

X = 2Z
X = 3Y + $m
X+Y+Z = $T

You have three independent equations and three unknowns (X, Y, Z). You should be able to solve this in terms of $m and $T.