Answer from cs61c-ck (Allen Lee 16583554) for Question 1
c5 = g4 + (p4*g3) + (p4*p3*g2) + (p4*p3*p2*g1)
       + (p4*p3*p2*p1*g0) + (p4*p3*p2*p1*p0*c0)