Respuesta :

t=ms/(m+n)
t(m+n)=ms
tm+tn=ms
tm-ms=-tn
m(t-s)=-tn
m=-tn/(t-s)

Answer: m=-tn/(t-s)
t = ms / (m + n)

Cross multiply out.

t*(m + n) = ms

tm + tn = ms

tm - ms = -tn

Multiply both sides by -1

-1*(tm - ms) = -1*-tn

-tm + ms = tn  

ms - tm = tn

m(s -  t) = tn            Divide by (s - t)

m = tn / (s - t)

I hope this helps.