I have a problem with an atwood's machine problem. i have three tensions where T1 and T2 are on the left and T3 is on the right. Bottom left corner is block 2kg with T1 then another block 2kg with T2 on the left side. On the right side i have a block of 7kg with T3. I am asked to find T1 but i only know how to find T2???

Question

I have a problem with an atwood's machine problem. i have three tensions where T1 and T2 are on the left and T3 is on the right. Bottom left corner is block 2kg with T1 then another block 2kg with T2 on the left side. On the right side i have a block of 7kg with T3. I am asked to find T1 but i only know how to find T2???
any ideas maybe about a website link that might help