Calculating the Fourth Mass: A Rope and Four Masses

[Dekoy]

Homework Statement

2. There are four masses hanging by a rope from the
ceiling, as shown in the figure. Two of the tensions
and three of the masses have been measured.
Show that the fourth mass can be expressed as
m4 =[m1T2/(T1 − T2)]− m2 − m3.

Homework Equations

F=ma, F1=-F2, T=ma

The Attempt at a Solution

I think that (m1+m2+m3+m4)g=T1 and (m2+m3+m4)g=T2
I tried solving for g and substituting and try and solve for m4 but I just find it impssible to do.

 

[kuruman]

We can't help you unless we see the figure that goes with this question.

 

[Dekoy]

I tried copying and pasting from a pdf file but it didn't work but it's really easy actually I already figured it out, :). Thanks anyways.