Hi,
I ve been trying to workout an RL problem where Vs of 100\(\angle30\) and Is of 2\(\angle-10\) is applied to 2 impedances; Z1 = 25Ω and Z2 = R2+jXL. Can i convert the Vs to 100\(\angle40\) and Is to 2\(\angle0\) and work with them like that to find R2 and L ?

 

Yes - If it helps you solve the problem then shifting the source voltage phase angle and source current phase angle by the same value would be acceptable.

 

Another technique is to convert polar coordinates into rectangular. This way:
Vs=86.6+50j
Is=1.969-0.347j
Z1=25+0j=25
Z2=R2+jXL