mohon jawabanya ,no 2dan3 itu pakai caranya

2. Diketahui = I = 500 ma = 0,5 Ampere
                      R = 140 ohm
Ditanya = P =____?
P = I² x R
P = (0,5)² x 140
P = 0,25 x 140 = 35 watt (C)
3. Diketahui = R1 = 60 ohm,R2 = 120 Ohm, R3 =40 ohm, V = 6 volt
Ditanya= R.paralel=____?
R4 = 1/R1 + 1/R2
R4 = 1/60 + 1/120
R4 = 2/120 +1/120
R4 = 3/120
R4 = 120/3 = 40 Ohm
R.paralel = 1/R4 + 1/R3
R.Paralel = 1/40 + 1/40 = 2/40 
R.Paralel = 40/2 = 20 Ohm. (B)