What is the general equation for first law of thermodynamics? is it de =q +w or q=de+w

Rather it is more important to understand the terms.

In physics we take work done by the system is positive. Whereas in chemistry we take work done on the system is positive.

So if you put the value accordingly with correct sign you will get the same result

In chemistry we are interested in internal energy of the system. So dU = q+w is more correct. In physics we are interested in work as we study about machine so we should be able to get work done by the system so q= du+w. But again both equation are correct with correct sign convention

will give same magnitude

see in both places the equation is taken are different. im confused what to use when

See the ist page equation is generally that we see chemistry text. Again I am saying 2nd one is also correct if you know to put the value with the correct sign.

Don't be confused

which eq shud i use sir? im not getting what sign to use when bcoz the material is not specifying conditions

Just use this when the work done by the system put -ve sign. Work done on the system is +ve. If heat is given to the system then q is +ve. If heat is taken out then q is -ve.

Both equation will give you same result. But to be safer side use this du= q+w

i will add those signs to du= Q +w?

yes ofcourse

sir what is the meaning of work done with respect to system?

please send where it is written

this one sir and can we use the signs you told to dU= q-W?

in both places different form if equation are used.. im confused what to use when

this one also

see sourav...with what respect we consider....accordingly it changes

It changes accordingly how work is defined

work done with respect to system means work done on the system?

dear sourav is your doubt clear for this