1–23 Figure P1–22 shows an electric circuit with a voltage and a current variable assigned to each of the six devices. Use power balance to find v4 when v1 = 20V, i1 = −2A, p2 = 20W, p3 = 10W, i4 = 1 A, and p5 = p6 = 2:5W. Is device 4 absorbing or delivering power?