Hope this helps. Gurus, please correct me if I am wrong.
a. Ia = Ian = Van / Z = 120/(36+j48) = 2 ang -53.1 A
b. Va'n = Van + R * Ia = 120 + 4*2 ang -53.1 = 124.96 ang -2.93 V
c. P total loss = 3 * |Ia|^2 * R = 3*2^2*4 = 48 W
d. P total input = 1.732 * |Va'b'| * |Ia'| * cos(theta) = 1.732 * (124.96*1.732) * 2 * cos(53.1-2.93) = 480.21 W
Ilan.
PS: what happens when I copy and paste the symbols from MS word, will it work?