Masses m1 and m2 are connected by a light string (A) over a light, friction-less pulley (B). The Axle of Pulley B is connected to another light string (C), which goes over a light, friction-less pulley (D), to a mass m3. Pulley D is attached to the ceiling by an attachment to its axle. The system is released from rest. I'm trying to find the acceleration of m1, m2, m3, and pulley B, as well as the tension on string A and string C. I've split the whole system into two smaller systems, where [m1, m2, string A, and pulley B] is system 1 and [m1, m2, m3, pulley B and D, and strings A and C] (everything in the system) is system 2. relevant relationships/equations: F=ma, Tsys1 = (m1+m2)g - (m1+m2)asys1 m1+m2+m3 = M and (I think): asys2 = [(m3 - (m1+m2)) * g] / M I'm not sure if I just can't do the algebra here, or if I'm missing something big. I have two pages of me trying to figure it out, but I need some insight. Thank you.