C1m1t1-c1m1t=c2m2t-c2m2t2
c2m2t+c1m1t=c1m1t1+c2m2t2
t (c2m2+c1m1) = c1m1t1+c2m2t2
t = (c1m1t1+c2m2t2) / (c2m2+c1m1)
C1m1t1-c1m1t=c2m2t-c2m2t2
c2m2t+c1m1t=c1m1t1+c2m2t2
t (c2m2+c1m1) = c1m1t1+c2m2t2
t = (c1m1t1+c2m2t2) / (c2m2+c1m1)