40<50degrees + 20<-30 degrees, I get how to convert to rectangular, I got 43.03 + j20.64, but converting it back to polar.... how exactly do you do so? The answer is 47.72<25.63degrees..... my book doesn't explain it. Also with (2+j4)(3-j5).... how exactly do you tackle this sort of problem? I tried the FOIL method and it didn't exactly work. Thank you!