little math help on schematic

[Rich Grise]

_Not_ counting the 1k resistor? It's in there isn't it?, so how do
you propose to do away with it? Oh, I get it... it's inconvenient for
you to deal with, so you want to want to make it go away so you don't
have to deal with it. Never mind that the load isn't reactive so you
can't realize a voltage greater than the DC source voltage feeding it,
you still want to assume that, somehow, 32VDC is there.

Well, have you accounted for the possible voltage compliance of the two
current sources?

Cheers!
Rich

 

[Rich Grise]

Well, I've jumped on you prematurely a few branches back.

And yes, I did so with a needling attitude. Glad to see that there hasn't
been any permanent damage so far.

Cheers!
Rich

 

[Fred Abse]

((Va-8)/1k)-50mA - (Va / 12k) - (Va/6k) + 90mA - (Va/4k) = 0 but that
does not yield 32v

Quite true.

However, ((8-Va)/1k) -50mA - (Va / 12k) - (Va/6k) + 90mA - (Va/4k) = 0
*does* yield 32V for Va

Look at the first term: Currents are positive if they flow *into* a node.
Hence (8-Va)/1K is the correct current with reference to node "A"

I leave it to you to verify the result.